Perl | wantarray() Function

wantarray() function in Perl returns True if the currently executing subroutine expects to return a list value, and false if it is looking for a scalar value.

Syntax: wantarray()

Returns: true for list value and false for scalar values

Example 1:

#!/usr/bin/perl -w

# Subroutine to call wantarray() function
sub geeks
{
    return(wantarray() ? ("Geeks", "For", "Geeks") : 1);
}

# Calling the subroutine
# in scalar and array context
$value = geeks();
@value = geeks();

# Printing the values in both contexts
print("Value in Scalar context: $value\n");
print("Value in List Context: @value");

Output:

Value in Scalar context: 1
Value in List Context: Geeks For Geeks

Example 2:

#!/usr/bin/perl -w

# Subroutine to call wantarray() function
sub geeks
{
    if(wantarray())
    {
        # Addition of two numbers when
        # wantarray() function is called
        # in list context
        $c = $a + $b;
    }
    else
    {
        # When wantarray() is called
        # in Scalar context
        return 1;
    }
}

# Driver Code
$a = 10; $b = 20; $c = 0;

# Calling Subroutine in scalar and list contexts
$value = geeks($a, $b);
@value = geeks($a, $b);

# Printing values in both the contexts
print("Value when called in Scalar context: $value\n");
print("Value when called in List Context: @value");

Output:

Value when called in Scalar context: 1
Value when called in List Context: 30