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Perl |标量关键字

原文:https://www.geeksforgeeks.org/perl-scalar-keyword/

Perl 中的标量关键字用于将表达式转换为标量上下文。这是对标量上下文表达式的有力评估,即使它在列表上下文中运行良好。

语法:标量表达式 返回:一个标量值

例 1:

Perl 语言

#!/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

例 2:

Perl 语言

#!/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


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