함수 map()

map

1 JavaScript

JavaScript .map() 문서를 참고하십시오.

var numbers = [1, 4, 9];
var roots = numbers.map(Math.sqrt);
// roots is now [1, 2, 3]
// numbers is still [1, 4, 9]

var numbers = [1, 5, 10, 15];
var doubles = numbers.map(function(x) {
   return x * 2;
});
// doubles is now [2, 10, 20, 30]
// numbers is still [1, 5, 10, 15]

2 PHP

PHP array_map() 문서를 참고하십시오.

$a = [2, 3, 4];
$b = array_map( function($n) { return $n*$n; }, $a);
print_r( $b );
# Array
# (
#     [0] => 4
#     [1] => 9
#     [2] => 16
# )

3 Python

Python 3

numbers = [1, 2, 3, 4, 5, 6]
print( list(map(lambda x: x * 2 - 1, numbers)) )
# [1, 3, 5, 7, 9, 11]

numbers = [1, 2, 3, 4, 5, 6]
print( [x * 2 - 1 for x in numbers] )
# [1, 3, 5, 7, 9, 11]

4 Perl

my @numbers = (1, 2, 3, 4, 5, 6);
print map { $_* 2 - 1 } @numbers;
# 1357911

5 R

R sapply() 문서를 참고하십시오.

sapply(c(2,3,4), function(n) { n*n })
## [1]  4  9 16

6 같이 보기

• reduce
• filter
• lambda function
• list comprehension
• 맵리듀스 프로그래밍 모델