delete() Function, Hash Element, Syntax, Example, Perl Programming Tutorial

Tutorials

Perl

Topic

What is delete() Function in Perl programming?

Explanation

The delete() function deletes a value or a hash completely.

Syntax:

    delete hash;

Example:

    #! C:\programfiles\perl\bin\perl
    print "content-type: text/html\n\n";
    %color = ('1' => 'Green' , '2' => 'Orange', 
              '3' => 'Blue', '4' => 'Pink');
    print %color;
    print "<br>";
    $del = delete($color{'3'});
    print "The Hash after Deleting:\n";
    print "<br>";
    print %color;

Result:

    4Pink1Green3Blue2Orange
    The Hash after Deleting:
    4Pink1Green2Orange

In the above example the hash element "blue" is deleted and the rest of the hash elements are displayed.

Deleting a Hash:
Example:

    #! C:\programfiles\perl\bin\perl
    print "content-type: text/html\n\n";
    %name = ('Tom',26,'Peter',51,'Jones', 23, 'John', 43);
    foreach $key (keys %name) 
    {
      delete $name{$key};
    }
    print "Values of Hash after deleting\n";
    print scalar grep defined($_),values %name;

Result:

   Values of Hash after deleting 0

In the above example a hash is deleted completely using a loop, then the hash is checked for any values and the result displays zero.

Perl Hash Element delete() Function