perl function undef

The undef function in Perl is used to undefine the value of a variable. When a variable is undefined, it does not contain a value and its state is considered as null or undefined. This function can be used to free the memory that was being used by a variable.

Here's an example:

my $x = 10;
print "Value of x before undef: $x\n";

undef $x;
print "Value of x after undef: $x\n";

Output:

Value of x before undef: 10
Value of x after undef:

In the above example, we define a variable $x and initialize it with the value 10. Then, we print the value of $x before calling the undef function. After that, we call undef $x to undefine the value of $x. Finally, we print the value of $x again, and this time it doesn't have any value assigned to it, since we have used the undef function to undefine it.