javascript add property to element code example

Example 1: how to add property to object in javascript

var data = {
    'PropertyA': 1,
    'PropertyB': 2,
    'PropertyC': 3
};

data["PropertyD"] = 4;

// dialog box with 4 in it
alert(data.PropertyD);
alert(data["PropertyD"]);

Example 2: set property dom javascrpt

document.getElementsByTagName("H1")[0].setAttribute("class", "democlass");

Example 3: add property to object javascript

let yourObject = {};

//Examples:
//Example 1
let yourKeyVariable = "yourKey";
yourObject[yourKeyVariable] = "yourValue";

//Example 2
yourObject["yourKey"] = "yourValue";

//Example 3
yourObject.yourKey = "yourValue";

Example 4: add property with value in js

var myObject = {
    sProp: 'some string value',
    numProp: 2,
    bProp: false
};