Shift / Unshift Function, Add / Remove elements from the beginning, Array Functions

Tutorials

Perl

Topic

What is Shift, Unshift Function?
How to add / remove an element from the beginning of an array?

Explanation

Add Elements to an Array:
Unshift Function:

Unshift is used to add an element to the begining of an array.

Syntax:

     unshift ARRAY, LIST;

In the above syntax the "ARRAY" specifies the array to which the elements in "LIST" are to be added in the begining.

Example:

    #! C:\programfiles\perl\bin\perl
     print "content-type: text/html\n\n";
     @color = ("red", "blue");
     unshift (@color, "green");
     $,="\n";
     print @color;

Result

    green red blue

The array @color will have three elements with "green" as the first element.

Remove Elements from an Array:
Shift Function:

Shift is used to remove an element from the begining of an array.

Syntax:

     shift (ARRAY);

In the above syntax "ARRAY" specifies the array from which an element need to be removed from the begining.

Example:

    #! C:\programfiles\perl\bin\perl
    print "content-type: text/html\n\n";
    @color = ("red", "blue", "green");
    shift (@color);
    $,="\n";
    print "@color";

Result:

     blue green

In the above example, the first element "red" is removed from the begining of an array, then the rest of the array is displayed.

Shift and Unshift Functions in Perl