For this, use the “this” keyword.ExampleFollowing is the code −class Employee {     constructor() {         this.tempObject = [             {                 firstName: "David",                 setTheAnotherFirstName() {                     this.firstName = "Carol";                 },             },         ];     } } var empObject = new Employee(); empObject.tempObject[0].setTheAnotherFirstName(); console.log("The Change First Name is=" + empObject.tempObject[0].firstName);To run the above program, you need to use the following command −node fileName.js. Here, my file name is demo220.js.OutputThe output is as follows −PS C:\Users\Amit\JavaScript-code> node demo220.js The Change First Name is=Carol

To add property, use map(). Let’s say the following is our array −const firstname = ['John', 'David', 'Bob'];Following are our array of objects −const studentDetails = [    {       firstname: 'Carol',       marks: 78    },    {       firstname: 'Mike',       marks: 89    },    {       firstname: 'Bob',       marks: 86    } ]; ExampleFollowing is the code −const firstname = ['John', 'David', 'Bob']; const studentDetails = [    {       firstname: 'Carol',       marks: 78    },    {   ... Read More

Let’s say we have the following variables −var value1 = 10; var value2 = 10.15;Use the Number() condition to check that a number is float or integer −Number(value) === value && value % 1 !== 0; }ExampleFollowing is the code −function checkNumberIfFloat(value) {    return Number(value) === value && value % 1 !== 0; } var value1 = 10; var value2 = 10.15; if (checkNumberIfFloat(value1) == true)    console.log("The value is float=" + value1); else    console.log("The value is not float=" + value1); if (checkNumberIfFloat(value2) == true)    console.log("The value is float=" + value2); else    console.log("The value is not ... Read More

For ternary operator alternative, simply use if else in JavaScript. Let’s say, we have two numbers −var number1=12; var number2=12;To compare, we can use if else, instead of the ternary operator −if(number1==number2) console.log("true"); else console.log("false");ExampleFollowing is the code −var number1=12; var number2=12; var result=(number1==number2)?true:false; console.log(result); if(number1==number2)    console.log("true"); else    console.log("false");To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo217.js.OutputThe output is as follows −PS C:\Users\Amit\JavaScript-code> node demo217.js true trueRead More

To remove, use remove() and append() to add option in already created select list. Let’s say the following is our select −    JavaScript    MySQL ExampleFollowing is the code to remove all the options and add a new one − Live Demo            Document           JavaScript       MySQL        $('#demo')    .find('option')    .remove()    .end()    .append('MongoDB')    .val('MongoDB')    ; To run the above program, save the file name anyName.html (index.html). Right click on the file and select the option “Open with Live Server” in VS Code editor.OutputThe output is as follows −

Use tag for a new line.ExampleFollowing is the code −            Document           My Name is David Miller        document.getElementById("headingDemo").innerHTML = "My Favourite Subject is JavaScript" + '' + "I live in AUS."; To run the above program, save the file name anyName.html (index.html). Right click on the file and select the option “Open with Live Server” in VS Code editor.The output is as follows −

To fix this, use the concept of this keyword. User another variable to hold the value of object, to use that inside the inner function.ExampleFollowing is the code −function Employee() {    this.technologyName = "JavaScript";    var currentTechnologyName = this;    function workingTechnology() {       console.log("I am working with " + currentTechnologyName.technologyName + " Technology");    }    workingTechnology(); } var currentTechnology = new Employee();To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo216.js.The output is as follows −PS C:\Users\Amit\JavaScript-code> node demo216.js I am working with JavaScript Technology

To display variables on console, use document.getElementById(“”).ExampleFollowing is the code − Live Demo            Document        const data = document.getElementById("printTheData");    console.log(data); To run the above program, save the file name anyName.html (index.html). Right click on the file and select the option “Open with Live Server” in VS Code editor.OutputThe output is as follows −Output in the console −

Let’s say the following are our radio buttons, which we have set checked −Gender Male FemaleTo uncheck, set the checked property to false using prop() in jQuery −$('input[id="yourChoice"]:checked').prop("checked", false);ExampleFollowing is the code − Live Demo            Document    Gender    Male     Female    $('input[id="yourChoice"]:checked').prop("checked", false); To run the above program, save the file name anyName.html (index.html). Right click on the file and select the option “Open with Live Server” in VS Code editor.OutputThe output is as follows −

To make checkboxes impossible to check, set disabled property to true −JavaScriptFollowing is the code −ExampleFollowing is the code − Live Demo            Document    List Of Subject names    MySQL    JavaScript    MongoDB To run the above program, save the file name anyName.html (index.html). Right click on the file and select the option “Open with Live Server” in VS Code editor.OutputThe output is as follows −You cannot check the checkbox value above since we have disabled it.