Lodash - findIndex method

Syntax

_.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.

Arguments

• array (Array) − The array to inspect.

• [predicate=_.identity] (Function) − The function invoked per iteration.

• [fromIndex=0] (number) − The index to search from.

Output

• (number) − Returns the index of the found element, else -1.

Example

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.

Command

\>node tester.js

Output

0
0