The Lodash _.forIn() Method Iterates over keys and values of the given object and invokes iteratee function for each property. The iteratee is invoked with three arguments: (value, key, object). Iteratee functions may exit iteration early by explicitly returning false.
Syntax:
_.forIn( object, iteratee_function)
Parameters: This method accepts two parameters as mentioned above and described below:
- object: This is the object to find in.
- iteratee_function: the function that is invoked per iteration.
Return Value: This method returns an object.
Example 1:
// Defining Lodash variable const _ = require( 'lodash' );   var users = {   'a' : 1,   'b' : 2,   'c' : 3 };    _.forIn(users, function (value, key) {   console.log(key); }); |
Output:
a b c
Example 2:
// Defining Lodash variable const _ = require( 'lodash' );   var users = {   'a' : 1,   'b' : 2,   'c' : 3 };    _.forIn(users, function (value, key) {     if (value > 1) {         console.log(key, value);     } }); |
Output:
b 2 c 3
Note: This will not work in normal JavaScript because it requires the lodash library to be installed and can be installed using the following command:
npm install lodash