如何在CoffeeScript中将理解结果收集到数组中？

Question

我不是在每个匹配值上调用一个函数,而是想获取值数组['broccoli', 'spinach'],但我不断遇到编译器错误.有人能解释一下我的误解吗？

# Health conscious meal.  - This example is from http://coffeescript.org/#loops
foods = ['broccoli', 'spinach', 'chocolate']
eat food for food in foods when food isnt 'chocolate'

# Failed Attempt #1 - Unexpected TERMINATOR
arr = for food in foods when food isnt 'chocolate'

# Failed Attempt #2 - Unexpected ')'
arr = (for food in foods when food isnt 'chocolate')

Answer 1

你错过了理解应该返回的值(这是eat food原始的,但你想要food未修改的返回).所以代替:

for food in foods when food isnt 'chocolate'

你要:

food for food in foods when food isnt 'chocolate'

(虽然如果你的目标是现代JavaScript实现,那么使用类似的东西可能会更具可读性foods.filter (food) -> food isnt 'chocolate'.)