CoffeeScript For 循環(huán)

For 循環(huán)

問題

你想通過一個(gè)for循環(huán)來迭代數(shù)組、對(duì)象或范圍。

解決方案

# for(i = 1; i<= 10; i++)
x for x in [1..10]
# => [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]

# To count by 2
# for(i=1; i<= 10; i=i+2)
x for x in [1..10] by 2
# => [ 1, 3, 5, 7, 9 ]

# Perform a simple operation like squaring each item.
x * x for x in [1..10]
# = > [1,4,9,16,25,36,49,64,81,100]

討論

CoffeeScript使用推導(dǎo)（comprehension）來代替for循環(huán)，這些推導(dǎo)最終會(huì)被編譯成JavaScript中等價(jià)的for循環(huán)。