Trending March 2024 # How Does Printf Function Work In Perl With Examples # Suggested April 2024 # Top 7 Popular

You are reading the article How Does Printf Function Work In Perl With Examples updated in March 2024 on the website Katfastfood.com. We hope that the information we have shared is helpful to you. If you find the content interesting and meaningful, please share it with your friends and continue to follow and support us for the latest updates. Suggested April 2024 How Does Printf Function Work In Perl With Examples

Introduction to Perl printf

Web development, programming languages, Software testing & others

Syntax:

The Perl scripts have default keywords, functions and scalar variables that means the variable accepts only the single value. It can be any numbers, letters, characters, digits with operators, but the first character of the variable always must be the letter or symbol; like the underscore operator, it’s not a digit.

$ variable name = value; printf(" ", $variable name); ---some Perl script logics--- How does the printf Function Work in Perl?

The Perl script printf() method prints only the user datas with the specified format specifiers on the screen. Actually, the function prints only the values, which is interpreted using the List datas through via using some format specifiers with the current result as the output. The filehandle concept is used for more space in the printf function, which handles the errors and exceptions by using exception classes and modules but the printf() function that prints the outputs by using some format specifiers. Generally, the printf function used some properties which are related to their fields and attributes.

Like that this function as many of the properties are to be same as the print function in the script. That’s the way it shows the better output format, which has already related to their user inputs. This is more similar to the field specifiers with co-related to their text string format specifiers with some delimiters like comma, semi-colon, underscore etc. Using some Regular Expressions concepts, the user inputs are to be validated and evaluated at the back end codes, showing the output on the user screen.

Examples of Perl printf

Given below are the examples of Perl printf:

Example #1

Code:

$var = 1562.45; $strn = ("Welcome To My Domain"); printf("Hi user your input is $%6.3f and converted output is %snn", $var, $strn);

Output:

Explanation:

In the above example, we used two variables like $var and $strn, and both the variables are used with some formats like $var variable assigned values are only the float type of numbers so the decimal point of results to be expected once the given variable is executed on the script like that it will be printed on the user screen.

Same time the next variable $strn accepts only the string values like “Welcome to My domain”, so it’s a string format it specifies the user information’s the printf function which has passed the calls to the string and also the field is specified to the variables and then it will insert into the memory locations for separate positions.

Example #2

Code:

printf("Welcome To My Domain:n"); printf("'%7d'n", 7); printf("'%7d'n", 596903); printf("'%7d'n", -94758); printf("'%7d'n", -904685); printf("n"); printf("Have a Nice Day:n"); printf("'%-8d'n", 785); printf("'%-8d'n", 1023894785); printf("'%-8d'n", -923487568); printf("'%-8d'n", -1293475); printf("n"); printf("n"); printf("Thanks for your interest in our application:n"); printf("'%09d'n", 3); printf("'%09d'n", 223); printf("'%09d'n", 9234687); printf("'%09d'n", -9238747); printf("'%09d'n", -2390478); printf("'%04d'n", 23); printf("'%04d'n", 'Welcome'); printf("'%04d'n", 'Welcome34'); printf("'%04d'n", -9243747); printf("'%04d'n", -4590478); printf("'%02d'n", 'Tyujk'); printf("'%02d'n", 'udg 4857 sdhfg'); printf("'%02d'n", 9238747); printf("'%03d'n", -93476538747); printf("'%02d'n", -239754478);

Output:

Explanation:

In the second example, we have used the same printf function in different ways. We can pass the inputs in numbers that will be the integer, float, decimal, short, long and double; it can be any of the types passing into the function, and it is converted into the required output format.

Some formats will follow the rules and control the fields with some heights, widths, and even other fields like printing left-justified, right-justified and zero-filled numbers stored in the variables for calculating their functions and storages the memory locations. It accepts both positive and negative numbers followed by its signatures and its relevance to their usages.

Example #3 printf("'%4s'n", "Welcome"); printf("'%76s'n", "Welcome"); printf("'%-76s'n", "Welcome"); printf("Welcome To My Domainn"); printf("Have a Nice Dayn"); printf("kjadgvds hasjkgdf ashdjfh jsdhfhj ajsgn"); printf("WelcometTo My Domainn"); printf("jasg hsagdfj skjdfhk skdh shfj sjn"); printf("Welcomen To My Domainn"); printf("kjshdfj kjahksj nkjh 2734 shj2983 3974y kn"); printf("C:UsersKripya-PCDocumentsarticles\n"); printf("hsdfjg jhajs kjaskdj kjaksd jaskn"); printf("weh jkhj kawj kwejk jwlkl lkwqejkwlkqjlkn"); printf("'%.3f'nn", 873.974); printf("87v hk jskj oi3y khk38 i347 bi3748n"); printf("'%.5f'n", 873.975); printf("jdshj38 3784 3748687j he83sk 94n"); printf("'%6.4f'n", 748.28374); printf("u3928 oiwu498y bu4589 io349 b3974n"); printf("'%7.14f'n", 734.837495); printf("3749 yiwe b843 sekk48905 je48n"); printf("'%06.4f'n", 83.8346); printf("2638 hy3w8 j8939475 jbi34y8b wu4985b 3u984y bu498n"); printf("'%-6.3f'nn", 857.98374); printf("26837 hjkwehr234yv hj gu4 s h  jkh jkjkh 3987n"); printf("'%-5.25f'n", 8347958.892365);

Output:

Explanation:

In the printf() function, we used both numbers and string characters in various format specifiers, and even some comparison operators are used and called with the same reference names. Because the printf function used some operators allowed with string formats and it has generated the reports with formats and even though the formatted holds with the some numbers that can be called through with the help of some conversions.

And these conversions will used some operators like the % sign with the end of the characters even though the same number of characters are assigned through its conversions. Using some exponential notations is required for the printf function.

Conclusion

In conclusion, they must have some built-in methods for printing the outputs on the screen for each programming languages. Likewise, each method has its own attributes and properties for showing its results as much as needed from the user perspective. In Perl, the printf function used some format specifiers for displaying the outputs on the user screen.

Recommended Articles

This is a guide to Perl printf. Here we discuss the introduction; how does the printf function work in Perl? and examples, respectively. You may also have a look at the following articles to learn more –

You're reading How Does Printf Function Work In Perl With Examples

Examples On How Does Class Work In Perl

Definition of Perl Class

Web development, programming languages, Software testing & others

How to Declare Perl Class?

The procedure is as follows.

It is very easy and simple to declare. To declare any class we need to mention package keyword before the class name.

Syntax:

Package class_name;

Parameter:

Below is a parameter description of Perl declare syntax.

Package: Package is nothing but a specified namespace within the Perl code or program which contains sub-routines or user-defined variables. The package is very important at the time of declaring the class.

Class name: We can define any class name to the program in Perl. But it is specific to the program which we have implemented.

A package name in perl class is subroutines or a user-defined variable. We can reuse this again in the code.

Package in perl will provide namespace within the program mostly which contains subroutines and variables.

The scope of class or package will end of the file or until we cannot create another package in one file.

Below is the example to declare per class is as follows.

Example:

Package declare_perlClass;

In the above example, we have declared class name as declare_perlClass. This class corresponds to a package name.

Before declaring declare_perlClass class firstly we need to load the package in Perl.

A loaded package is used in throughout the program. The scope of the package is throughout the program or until we define another package.

How does Class Work in Perl?

The working is as follows:

It is defined as it is a package that having constructor to create perl object, this object is having any type of variable but mostly it is a reference to array or hash is used.

It is nothing but a concept of data structures. It defines the object of data in perl.

To define we need to build a package first, the package is nothing but sub-routines or user-defined variables.

The object is nothing but an instance of the class.

It is very easy and simple to define, Itl is corresponding to a package of perl in its simplest form.

It is most important and useful in Perl to define Perl’s object.

We have to take the example of class as an employee. We have defining member function and data members using the class as an employee.

There may be an employee with different names and structures but all of them have some common characteristics like emp_id, emp_dept, and emp_name.

Here we have to define an employee as a class with emp_id, emp_dept, and emp_name as data members.

We have also used a bless function.

Syntax bless function:

bless name_of_object, name_of_class;

We can also create an object by using a perl class. We have to create an object based on the class name.

Data member in perl class is nothing but data variables and member function is a function which manipulated the variables.

In the below example, we have to define member variable as emp_id, emp_dept and emp_name.

We can define any class name to the program in perl. But it is specific to the program which we have implemented.

In the above example we have to define class name as employee and data member as emp_id, emp_dept and emp_name.

Examples

The examples are as follows:

Example #1 – Using bless function in perl class:

In the below example, we have created perl class using bless function. We have created a class name as an employee.

Member variables of class name is ’emp_id’ and ’emp_salary’.

We have defined a bless function. In bless function, we have to define object name and class name.

We have also define constructor of employee class name as new_emp to define member variables.

Code:

use strict; use warnings; package employee; ## Constructor of employee class. sub new_emp{ #the package name 'employee' is in the default array shift. my $class = shift; #object of a class. my $self = { }; #blessing with object name and class name bless $self, $class; #returning object from constructor return $self; } 1; print "emp_id:- 101n"; print "emp_salary:- 25000n"; 

Example #2 – creating class and using objects

In the below example we have created perl class using an object. We have created class name as an employee.

Member variables of class name is ‘Employee_FirstName’ and ‘Employee_LastName’.

We have defined a bless function. In bless function, we have to define object name and class name.

We have also define constructor of employee class name as employee_data to define member variables.

Code:

use strict; use warnings; package employee;   ## This is the class of employee. sub employee_data    ## Constructor of employee class. { # Shift is default array will used in 'employee' class and then assign # it to employee class variables my $class_name = shift; my $self = { }; # using bless function. bless $self, $class_name; # returning object from constructor of employee_data. return $self; } # Object creating name as employee from employee_data and calling a constructor. my $Data = employee_data employee("Emp_FirstName:- ABC", "Emp_LastName:- PQR"); # printing the data

Output:

Recommended Articles

We hope that this EDUCBA information on “Perl Class” was beneficial to you. You can view EDUCBA’s recommended articles for more information.

How Strlen() Function Work In Php With Examples

Introduction to PHP strlen()

A large set of built-in functions make it easier for the coder or the developer to deal with string-related operations in PHP. The strlen() is one of the popular functions we can say of the PHP string to get the length of the string. As its name has been formed by combining two words, str, and len, str refers to the word string, and the length is the length itself. This function will return the length of the given string. This can be used to get the length of the string of any substring whenever required in the program.

Start Your Free Software Development Course

Web development, programming languages, Software testing & others

Syntax:

strlen(String)

strlen: It is the function itself.

String: This is the only parameter that takes as a string.

Return Type:

This returns the length of the string, and it will always be an Integer. There is nothing much with the syntax of this function.

How strlen() Function work in PHP?

Before moving ahead with the strlen, we must have a strong first upon which this function will be applied. It takes the string as a parameter and returns the length of that given string. We can use the characters, special characters, URL, numeric values, and special sequence characters as part of the given string.

The user of strlen ()

Code:

$string = "WELCOME TO INDIA"; echo "Lenght of the given String is: "; echo strlen($string);

The above line of code given the length output as 16 as ‘WELCOME TO INDIA’ contains 16 characters, including the spaces.

Use of strlen() with the special sequence character as a string

We should be careful while passing a string containing special sequence characters like n,t,r, etc. As we can see, we n the 2 characters, but it will be counted as one while we will pass this as a parameter with the strlen() function.

Code:

$string = "rHello"; // a string $length = strlen($string); // lenghtof the string

The above line of code gives the output as 6 rather than 7. If we replace with any other character, then we will see the length 7 as an output. This could be a bit tricky while coding in php using the string strlen() function.

Examples of PHP strlen()

Given below are the examples mentioned :

Example #1

Get the length of the given string.

Code:

<?php $string = "WELCOME TO INDIA"; $Length = strlen($string); echo "Length of the given String is: ".$Length;

Output:

As we can see, there is not much in using this function due to the simplicity of this string function. We can consider this function as one of the easiest functions of the PHP string in nature, passing the string as a parameter to get the length.

Example #2

Get the length of the given string after removing all the spaces from that string.

Code:

<?php $string = "WELCOME TO INDIA"; $lenght = strlen($string); echo "Actual string: ".$string; echo "nLength of the given String including space: ".$lenght; $stringAfterRemovedSpace = str_replace(" ","",$string); echo "nActual String with no spaces: ".$stringAfterRemovedSpace; echo "nLength of the given String excluding space: ".strlen($stringAfterRemovedSpace);

Output:

Example #3

An example program demonstrates the use of strlen() function with the string containing the special character and the escape character.

Code:

<?php $string = "n WELCOME TO INDIA"; $Length = strlen($string); echo "Length of the given String is: ".$Length;

Output:

In the above program, when we count the character, it will come up to 19 in the manual, but it the program output, we can see that the length is showing 18. The length is showing one character lesser just because n is being counted as one.

Example #4

Code:

<?php $string = "WELCOME TO INDIA"; $length = strlen($string); echo "Actual String: ".$string; echo "nLength: ".$length; echo "nReverse String: "; { echo $string[$i]; }

Output:

In the above example code, we can see that the reversing string in php comes up with various stages, which include the getting length of the string, too, because the length of the given string helps the developer of the coder to loop through the end to the first position of the string.

Example #5

Length of the string and length of the reverse string of the same.

Code:

<?php $string = "n WELCOME Home!!!"; $length = strlen($string); echo "Actual String: ".$string; echo "nLength: ".$length; echo "nReverse String: "; $reverseString = ""; { $reverseString .= $string[$i]; } echo $reverseString; echo "nLength of the Reverse String: ".strlen($reverseString);

Output:

Conclusion

Built-in function strlen() can be used to get the length of the string. A developer should be aware enough of the functioning of this function. For example, if n, t, etc. contains in a string, then this 2-character special sequence can be considered as one. This function can be used to get the length of a string to make the further required operations. If we are writing our own custom string reverse code, then we can use this function to calculate the actual length of the string.

Recommended Articles

This is a guide to PHP strlen(). Here we discuss the introduction to PHP strlen(), how this function works, and programming examples. You may also have a look at the following articles to learn more –

Learn How Does The Trim Function Works In Perl?

Introduction to Perl trim

Perl trim removes the leading and trailing unwanted space of the Perl string. The trim is to cut the starting and ending whitespace of the Perl string and save the memory. Trim removes unnecessary white space of the Perl string and stores the required data in the database. The trim is useful to remove the space which is occurred before the initial and final character of the string. The trim is useful when the string wanted to cut both ends of unwanted space and save the necessary data.

Start Your Free Software Development Course

Syntax

The basic trim syntax is below.

This syntax is used to clear both sides of the white space of the string.

The basic Perl syntax used a regular expression to cut the leading and trailing unwanted space of the string.

The left side trim syntax is below.

$ left_perl_trim_variable =~  s/^s+//;

This syntax is used to clear the left side of the white space of the string.

The left side Perl syntax used a regular expression to cut the leading unwanted space of the Perl string.

The right-side trim syntax is below.

$ right_perl_trim_variable =~  s/s+$//;

This syntax is used to clear the right side of the white space of the string.

The right-side syntax used a regular expression to cut the trailing space of the Perl string.

How does the trim function work in Perl?

To download the Perl software and install it in your operating system of the device.

Make a file with the Perl extension in the device and save the file in the command line path.

Example:

helloo.pl or first pearl.pl

Create the string variable and Initialize with value for the trim.

$ perl_trim_function = "  Perl trim  ";

Use required trim syntax on the given Perl String variable.

Return the String after using trim syntax.

print " Perl trim string is below. n "; print" $ perl_trim_function n ";

The combined working step of trim is below.

$ perl_trim_function = "  Perl trim  "; print " original string is below. n "; print" $ perl_trim_function n "; print " Perl trim string is below. n "; print" $ perl_trim_function n "; Examples

Here are the following examples mentioned below.

Example #1

The basic trim example and Output.

Code:

$ perl_trim_function = "      Perl trim     "; print " original string is below. n "; print" $ perl_trim_function n "; print " Perl trim string is below. n "; print" $ perl_trim_function n n "; $ perl_trim_function1 ="    9, 8, 7, 6, 5    "; print " original value is below. n "; print" $ perl_trim_function1 n "; print " Perl trim value is below. n "; print" $ perl_trim_function1 n n n "; $ perl_trim_function2 = "     Perl trim, 1, 2    "; print " original value is below. n "; print" $ perl_trim_function2 n "; print " Perl trim value is below. n "; print" $ perl_trim_function2 n n n"; $ perl_trim_function3 = "     @, #, $, %, &    "; print " original value is below. n "; print" $ perl_trim_function3 n "; print " Perl trim value is below. n "; print" $ perl_trim_function3 n n n";

Output:

Example #2

Code:

$ perl_trim_function = "      left side Perl trim     "; print " original string is below. n "; print" $ perl_trim_function n "; $ perl_trim_function =~ s/^s+//; print " left side Perl trim string is below. n "; print" $ perl_trim_function n n "; $ perl_trim_function1 ="      9, 8, 7, 6, 5    "; print " original value is below. n "; print" $ perl_trim_function1 n "; $ perl_trim_function1 =~ s/^s+//; print " left side Perl trim value is below. n "; print" $ perl_trim_function1 n n n "; $ perl_trim_function2 = "      left side Perl trim, 1, 2    "; print " original value is below. n "; print" $ perl_trim_function2 n "; $ perl_trim_function2 =~ s/^s+//; print " left side Perl trim value is below. n "; print" $ perl_trim_function2 n n n"; $ perl_trim_function3 = "       @, #, $, %, &    "; print " original value is below. n "; print" $ perl_trim_function3 n "; $ perl_trim_function3 =~ s/^s+//; print " left side Perl trim value is below. n "; print" $ perl_trim_function3 n n n";

Output:

Example #3

The right side trims example and Output.

Code:

$ perl_trim_function = "      right side Perl trim     "; print " original string is below. n "; print" $ perl_trim_function n "; $ perl_trim_function =~ s/s+$//; print " right side Perl trim string is below. n "; print" $ perl_trim_function n n "; $ perl_trim_function1 ="      9, 8, 7, 6, 5    "; print " original value is below. n "; print" $ perl_trim_function1 n "; $ perl_trim_function1 =~ s/s+$//; print " right side Perl trim value is below. n "; print" $ perl_trim_function1 n n n "; $ perl_trim_function2 = "      right side Perl trim, 1, 2    "; print " original value is below. n "; print" $ perl_trim_function2 n "; $ perl_trim_function2 =~ s/s+$//; print " right side Perl trim value is below. n "; print" $ perl_trim_function2 n n n"; $ perl_trim_function3 = "       @, #, $, %, &    "; print " original value is below. n "; print" $ perl_trim_function3 n "; $ perl_trim_function3 =~ s/s+$//; print " right side Perl trim value is below. n "; print" $ perl_trim_function3 n n n";

Output:

Example #4

The trim uses an array example and output.

Code:

@perl_trim_function = ("  basic  ","   perl       ","   trim   "); print " original string is below. n "; print" @perl_trim_function n "; print " Perl trim string is below. n "; print" @perl_trim_functions n n "; @perl_trim_function = ("  Left  ","   side    ","   perl       ","   trim   "); print " original string is below. n "; print" @perl_trim_function n "; @perl_trim_functions =  grep(s/^s+//g, @perl_trim_function); print " left side Perl trim string is below. n "; print" @perl_trim_functions n n "; @perl_trim_function = ("  right  ","   side    ","   perl       ","   trim   "); print " original string is below. n "; print" @perl_trim_function n "; @perl_trim_functions =  grep(s/s+$//g, @perl_trim_function); print " right side Perl trim string is below. n "; print" @perl_trim_functions n n ";

Output:

Description:

The grep() method is used for array elements and trim as per users requirements.

The g operator is used for the global variable and chooses all elements for trim.

Conclusion

Trim is useful for removing the whitespace of the string in Perl technology. The trim is saving the memory space of the database and removes unnecessary spaces of the Perl string.

Recommended Articles

This is a guide to Perl trim. Here we discuss How does the trim function works in Perl and Examples along with the codes and outputs. You may also have a look at the following articles to learn more –

How Does C++ Shuffle Work With Examples

Definition of C++ shuffle()

Web development, programming languages, Software testing & others

Syntax:

void shuffle (RandomAccessIterator first, RandomAccessIterator last, URNG&& g);

Let us check what each keyword and parameter signify in this function

We call the RandomAccessIterator. The first parameter points to the position of the first element in the range, which will be rearranged.

The second parameter points to the last element in the range, which will be rearranged. For this also, it will be pointing to random access iterator.

The last parameter, g, is a special function object that helps us generate random numbers. It is called a uniform random number generator.

The return value of this function will be none.

How does C++ shuffle Work?

Using the C++ shuffle function is easy. Let us check how it works.

Code:

{ for (int i: vec) { std::cout << i << ‘ ‘; } } int main() { std::shuffle(vec.begin(), vec.end()); shuf(vec); return 0; }

We must import the vector library to use the shuffle() function. The user-defined function displays the shuffled vectors. We have created a vector with a few numbers in the main function. The shuffle() function has a beginning and an end which takes the vector elements and shuffles them. Once this is done, we call the function to print the shuffled array. We have not specified the random generation function; hence it will take the default function, which can be used. It will rearrange the elements in the vector. The function will swap the value of each element with any other randomly picked element from the same vector. It works with generators that work like the rand() function. To use this function without a generator, we can use the random_shuffle(). Let us check a few examples to help us understand the function better.

Examples of C++ shuffle()

Following are the examples given below:

Example #1

using namespace std; int main () { unsigned num = chrono::system_clock::now().time_since_epoch().count(); shuffle (shuf.begin(), shuf.end(), default_random_engine(num)); cout << “The numbers after shuffling are:”; for (int& x: shuf) cout << ‘ ‘ << x; cout << ‘n’; return 0; }

Output:

Code Explanation: The above code is an example of a shuffle function. We have used the iostream, array, random, and Chrono libraries. Here the Chrono library is used to create a random generator. We have taken an array with a size of 8 integers. Here we have defined this array, and then we are using the random generator function using the Chrono library. We are generating a random number using the epoch() and now() function which is a part of the clock library. It creates a pattern using which the numbers are shuffled. Then we have called the shuffle function, where we define the start and end of the array, and the third parameter is the variable that stores the calculation for random number generation. We then print the randomly shuffled array at the end of the program. Below is the output of the above program.

Example #2

Code:

using namespace std; void edu_shuffle(int arr[], int n) { unsigned rnd = 0; shuffle(arr, arr + n, default_random_engine(rnd)); for (int i = 0; i < n; ++i) cout << arr[i] << " "; cout << endl; } int main() { int arr[] = { 18, 23, 30, 47, 87, 49}; int num = sizeof(arr) / sizeof(arr[0]); edu_shuffle(arr, num); return 0; }

Code Explanation: In this program, we have imported a library and created a user-defined function, edu_shuffle. This function first creates an unsigned integer variable that will store the random generation calculation. We then use the shuffle() function, passing the start and end of elements between which the shuffling should occur. In place of random generation, we have used an inbuilt function default_random_engine to create a random number. In the main function, we calculated the end of the elements sent to the edu_shuffle function. We have used the sizeof function. We have sent these as parameters to the user-defined function, which helps execute the shuffle() function. The output of the above function will be as below:

Advantages of C++ shuffle()

The shuffle function helps in generating a random sequence of numbers easily.

This function swaps numbers with internal elements quickly.

If no random generator function is specified, the shuffle() function default will be taken.

It is fast and efficient, which makes it easy to use

The randomness of numbers can be built and used with the C++98/03 standard.

Conclusion

The shuffle() function is an easy way of rearranging the elements of a vector or array. A random generator variable can be used to generate the pattern of random numbers. The library plays a role in defining the “else” pattern by utilizing the default functionality provided by the function. It actively swaps the elements within a given range. This range can be between any elements in the array. This function is similar to the random_shuffle() function. The only difference is shuffle() uses a uniform random number generator.

Recommended Articles

We hope that this EDUCBA information on “C++ shuffle()” was beneficial to you. You can view EDUCBA’s recommended articles for more information.

How Does Unnest Function Work In Postgresql?

Introduction to PostgreSQL Unnest

PostgreSQL unnest is the type of array functions; the unnest function in PostgreSQL is basically used to expand the array into rows. Unnest function is converting an array into a table-like structure; we can also generate a table structure of an array using unnest function in PostgreSQL. Unnest array function is very useful in PostgreSQL for expanding the array into the set of values or converting the array into the table structure. If we need a table-like structure of array simultaneously, we have to use the unnest function on the array on which we have converted array data into the table-like structure.

Start Your Free Data Science Course

Syntax:

Below is the syntax:

Unnest(Any_array_number (Any array element number which was we have used with unnest function) Unnest (Any_array_text (Any array element text which was we have used with unnest function) Select unnest (any_array (Number of text value which was used in array.)) Select unnest (any_array (Number of text value which was used in array.)) limit number;

Below is the parameter description syntax of Unnest array function:

Unnest: This function we defined in PostgreSQL to set the element in a table-like structure. We have used unnest element with text as well as number array. We must define the number or text element with the unnest array function in PostgreSQL.

Any array text: This is defined as using an array of text values to convert the array into the table-like structure in PostgreSQL by using unnest array function.

Any array number: This is defined as a number. Using the unnest array function, we have used any number values to convert an array into the table-like structure in PostgreSQL.

Select: This operation selects the array’s value using the unnest array function in PostgreSQL. Select operations are very useful and important while using unnest array function in PostgreSQL.

Limit: In PostgreSQL, we have also using the limit clause with unnest function in PostgreSQL. While using the limit clause will show the number as per the limit we have used with unnest function.

How does Unnest Function work in PostgreSQL?

The first overload of usefulness aims to transform the values from an array into a single array.

In the old version of PostgreSQL, when we have to convert an array into the table structure, we have to use an array with the cross join. After joining the array with cross join, we generated the same series.

After generating the series, all the array elements will be structured into the table using cross join and generate series function.

The below example shows that in the old version, we used cross join with generate series function to convert the array into the table structure.

Code:

SELECT test_unnest[A] as array_element FROM  (SELECT ARRAY[11, 12, 13, 14, 15, 16, 17, 18, 19, 20] As test_unnest) as gen_ser CROSS JOIN generate_series(1, 10) As A;

Output:

The above example shows that we have used array element as [11, 12, 13, 14, 15, 16, 17, 18, 19, 20]; we have used this array element with generate series function for converting an array into the table like structure.

We have also used cross join with the array element and generated a series function for converting an array into a table-like structure.

By using unnest function, we do not need to use a cross join or generate series function to convert an array into a table like structure. We have simply using unnest function with an array.

In PostgreSQL, we have also utilised an array for a number or text to create a table-like structure.

We can also use unnest function with an order by clause. Using an unnest function, we have an order by clause with a 1 in it.

We have also use the limit clause with unnest function. After using a limit clause, it will show the output as per the number which was we have used with the limit.

Examples of PostgreSQL Unnest

Different examples are mentioned below:

Example #1 – Unnest function with array as a number.

Below example shows that unnest function with array as a number. In the below example, we use an array of numbers as [1, 2, 3, 4, 5, 6, 6, 7, 8, 9, 10].

Code:

SELECT unnest(ARRAY[1, 2, 3, 4, 5, 6, 6, 7, 8, 9, 10]);

Output:

Example #2 – Unnest function with array as text.

Below example shows that unnest function with array as text. In the below example, we are using an array of text as [‘ABC’, ‘PQR’, ‘XYZ’, ‘ABC’, ‘PQR’, ‘XYZ’, ‘ABC’, ‘PQR’, ‘XYZ’, ‘ABC’, ‘PQR’, ‘XYZ’].

Code:

SELECT unnest(ARRAY['ABC', 'PQR', 'XYZ', 'ABC', 'PQR', 'XYZ', 'ABC', 'PQR', 'XYZ', 'ABC', 'PQR', 'XYZ']);

Output:

Example #3 – Unnest function with an order by clause.

Below example shows that unnest function with an order by clause. In the below example, we use an array of numbers as [1, 2, 3, 4, 5, 6, 6, 7, 8, 9, 10].

SELECT unnest(ARRAY[1, 2, 3, 4, 5, 6, 6, 7, 8, 9, 10]) order by 1;

Output:

Example #4 – Unnest function with limit clause.

Below example shows that unnest function with a limit clause. In the below example, we use an array of numbers as [1, 2, 3, 4, 5, 6, 6, 7, 8, 9, 10].

Code:

SELECT unnest(ARRAY[1, 2, 3, 4, 5, 6, 6, 7, 8, 9, 10]) limit 5; SELECT unnest(ARRAY[1, 2, 3, 4, 5, 6, 6, 7, 8, 9, 10]) limit 8;

Output:

Recommended Articles

We hope that this EDUCBA information on “PostgreSQL Unnest” was beneficial to you. You can view EDUCBA’s recommended articles for more information.

Update the detailed information about How Does Printf Function Work In Perl With Examples on the Katfastfood.com website. We hope the article's content will meet your needs, and we will regularly update the information to provide you with the fastest and most accurate information. Have a great day!