How to get keys from JavaScript Object?
In this post, we will see how to get the key set from the object in JavaScript. Below are some basic methods which I have learnt in my professional software development experience.
Let’s take the below Object for our learning
let map = {"Name" : "Harry", "DOB" : "16.02.1998" , "Age" : "22"};
keys()
Syntax
Object.keys();
This method returns an Array containing the keys of the Object. It maintains the order. If you want want to get the values from object use Object.values()
console.log(map.keys()); //["Name", "DOB", "Age"]
For loop
Using the simple for..loop
we can get the keys by iterating each pair in Object.
var keyList = []; var valueList = []; for(key in map){ keyList.push(key); valueList.push(map[key]); } console.log(keyList); //["Name", "DOB", "Age"]; console.log(valueList);// ["Harry", "16.02.1998", "22"];
Jquery
Below is the easy approach that would work in Jquery version 1.6+
var keys = []; keys = $.map(map, function(item, key) { return key; }); console.log(keys); //["Name", "DOB", "Age"];
For each loop
In ECMAScript forEach
method, this will iterate over the object and return the keys.
var keyList = []; Map.forEach(obj => { keyList.push(obj); }); console.log(keyList); //["Name", "DOB", "Age"];