主题
findLastIndex
js
_.findLastIndex(array, [predicate=_.identity], [fromIndex=array.length-1])
此方法与 _.findIndex
类似,不同之处在于它从右到左迭代 collection
的元素。
¥This method is like _.findIndex
except that it iterates over elements of collection
from right to left.
新增于
¥Since
2.0.0
参数
¥Arguments
array
(数组):要检查的数组。¥
array
(Array): The array to inspect.[predicate=_.identity]
(函数):每次迭代调用的函数。¥
[predicate=_.identity]
(Function): The function invoked per iteration.[fromIndex=array.length-1]
(数值):要从中搜索的索引。¥
[fromIndex=array.length-1]
(number): The index to search from.
返回
¥Returns
(数值):返回找到的元素的索引,否则为 -1
。
¥(number): Returns the index of the found element, else -1
.
示例
¥Example
js
var users = [
{ 'user': 'barney', 'active': true },
{ 'user': 'fred', 'active': false },
{ 'user': 'pebbles', 'active': false }
];
_.findLastIndex(users, function(o) { return o.user == 'pebbles'; });
// => 2
// The `_.matches` iteratee shorthand.
_.findLastIndex(users, { 'user': 'barney', 'active': true });
// => 0
// The `_.matchesProperty` iteratee shorthand.
_.findLastIndex(users, ['active', false]);
// => 2
// The `_.property` iteratee shorthand.
_.findLastIndex(users, 'active');
// => 0