Perl map 函数

描述

This function Evaluates EXPR or BLOCK for each element of LIST. For each iteration, $_ holds the value of the current element, which can also be assigned to allow the value of the element to be updated.

Simply, Perl's map() function runs an expression on each element of an array, and returns a new array with the results.

语法

以下是此函数的简单语法 −

map EXPR, LIST

map BLOCK LIST

返回值

This function returns the total number of elements so generated in scalar context and list of values in list context.

示例

以下是显示其基本用法的示例代码 −

#!/usr/bin/perl -w

@myNames = ('jacob', 'alexander', 'ethan', 'andrew');
@ucNames = map(ucfirst, @myNames);

foreach $key ( @ucNames ) {
   print "$key\n";
}

执行上述代码时，会产生以下结果 −