Lodash findIndex method
语法：
_.findIndex(array, [predicate=_.identity], [fromIndex=0])
This method is like _.find except that it returns the index of the first element predicate returns truthy for instead of the element itself.
参数
array (Array) − The array to inspect.
[predicate=_.identity] (Function) − The function invoked per iteration.
[fromIndex=0] (number) − The index to search from.
输出：
(number) − Returns the index of the found element, else-1.
实例：
var _ = require('lodash');
var users = [
{ user: 'Sam', active: false },
{ user: 'Ted', active: true },
{ user: 'Julie', active: false }
];
var result = _.findIndex(users, function(user) { return !user.active; });
console.log(result);
result = _.findIndex(users, ['active', false]);
console.log(result);
Save the above program in
tester.js. Run the following command to execute this program.
命令：
输出：
