Perl | reset() Function

reset() function in Perl resets (clears) all package variables starting with the letter range specified by value passed to it. Generally it is used only within a continue block or at the end of a loop.

Note: Use of reset() function is limited to variables which are not defined using my() function.

Syntax: reset(letter_range)

Parameter:
letter_range: a range of letters that begin with a common character or a set of characters

Returns:
1, and resets all the variable in the given range

Example 1:

#!/usr/bin/perl -w

$var1 = 20;
$var2 = 15;

# Values before reset() function call
print "var1 value = $var1, ",
      "var2 value = $var2\n";

# Now reset all variables whose
# name starts with 'v'
reset('v');

# Values after reset() function call
print "var1 value = $var1, ",
      "var2 value = $var2\n";

Output:

var1 value = 20, var2 value = 15
var1 value = , var2 value =

Example 2:

#!/usr/bin/perl -w

$variable1 = 10;
$variable2 = 30;

# defining private variable using my()
my $variable3 = 40;

# Values before reset() function call
print "variable1 value = $variable1, ",
      " variable2 value = $variable2\n";
print "variable3 value = $variable3\n";

# Now reset all variables whose
# name starts with 'v'
reset('v');

# Values after reset() function call
print "variable1 value = $variable1, ",
      " variable2 value = $variable2, \n";
print "variable3 value = $variable3";

Output:

variable1 value = 10,  variable2 value = 30
variable3 value = 40
variable1 value = ,  variable2 value = , 
variable3 value = 40

In the code given in Example 2, variable 3 is defined using my() function and hence, its value shows no effect of the reset() function whereas other variable’s values get reset.