Perl | scalar keyword

scalar keyword in Perl is used to convert the expression to scalar context. This is a forceful evaluation of expression to scalar context even if it works well in list context.

Syntax: scalar expr
Returns: a scalar value

Example 1:

Perl

#!/usr/bin/perl -w

# Defining Arrays
@array1 = ("Geeks", "For", "Geeks");
@array2 = (1, 1, 0, 0, 9, 6);

# Concatenation of both arrays
@array3 = (@array1, @array2);

# Printing the Concatenated Array
# in List form
print "Array in List form: @array3\n";

# Conversion of Arrays to scalar context
@array3 = (scalar(@array1), scalar(@array2));

# Conversion to scalar returns
# the number of elements in the array
print "Array in scalar form: @array3\n";

Output:

Array in List form: Geeks For Geeks 1 1 0 0 9 6
Array in scalar form: 3 6

Example 2:

Perl

#!/usr/bin/perl -w

# Defining Arrays
@array1 = ("Welcome", "To", "Geeks");
@array2 = (1, 1, 0, 0, 9, 6);

# concatenation of both arrays
@array3 = ( @array1, @array2 );

# Printing the Concatenated Array
print "Concatenation of Arrays: @array3\n";

# Conversion of Arrays to scalar context to
# Evaluate Difference between size of arrays
@array3 = (scalar(@array2) - scalar(@array1));

# Printing the size Difference
print "Difference in number of elements: @array3\n";

Output:

Concatenation of Arrays: Welcome To Geeks 1 1 0 0 9 6
Difference in number of elements: 3