主题
forEach
js
_.forEach(collection, [iteratee=_.identity])
迭代 collection
的元素并为每个元素调用 iteratee
。迭代器使用三个参数调用:(value, index|key, collection)。迭代函数可以通过显式返回 false
提前退出迭代。
¥Iterates over elements of collection
and invokes iteratee
for each element. The iteratee is invoked with three arguments: (value, index|key, collection). Iteratee functions may exit iteration early by explicitly returning false
.
注意:与其他 "集合" 方法一样,具有 "length" 属性的对象像数组一样进行迭代。要避免此行为,请使用 _.forIn
或 _.forOwn
进行对象迭代。
¥Note: As with other "Collections" methods, objects with a "length" property are iterated like arrays. To avoid this behavior use _.forIn
or _.forOwn
for object iteration.
新增于
¥Since
0.1.0
别名
¥Aliases
_.each
参数
¥Arguments
collection
(数组|对象):要迭代的集合。¥
collection
(Array|Object): The collection to iterate over.[iteratee=_.identity]
(函数):每次迭代调用的函数。¥
[iteratee=_.identity]
(Function): The function invoked per iteration.
返回
¥Returns
(*):返回 collection
。
¥()*: Returns collection
.
示例
¥Example
js
_.forEach([1, 2], function(value) {
console.log(value);
});
// => Logs `1` then `2`.
_.forEach({ 'a': 1, 'b': 2 }, function(value, key) {
console.log(key);
});
// => Logs 'a' then 'b' (iteration order is not guaranteed).