Let’s say following is our array −var numbers=[10,50,80,60,89];To find the second largest element, the code is as follows −Examplevar numbers=[10,50,80,60,89]; var firstLargerNumber = Number.MIN_SAFE_INTEGER; var secondlargerNumber = firstLargerNumber; for(var tempNumber of numbers){    if(tempNumber > firstLargerNumber){       secondlargerNumber = firstLargerNumber;       firstLargerNumber = tempNumber;    }    else if(tempNumber > secondlargerNumber){       secondlargerNumber = tempNumber;    } } console.log("The second largest number="+secondlargerNumber);To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo138.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo138.js The second largest number=80

Let’s say the following is our button −SubmitOn the basis of button id, on form submission, generate an alert −$("#submitForm").click(function() {    alert("The Form has been Submitted."); });Example Live Demo Document CollegeId= CollegeName=  Submit    $("#submitForm").click(function() {       alert("The Form has been Submitted.");    }); To run the above program, save the file name “anyName.html(index.html)” and right click on the file. Select the option “Open with Live Server” in VS Code editor.OutputThis will produce the following output −After clicking the button, you can see the following output −

To get the yesterday date, first of all get the current date and subtract 1 from the current and use the function setDate(). The syntax is as follows −yourCurrentDateVariableName.setDate(yourCurrentDateVariableName.getDate() - 1);At first, get the current date −var currentDate = new Date();Now, get yesterday’s date with the following code −Examplevar currentDate = new Date(); console.log("The current date="+currentDate); var yesterdayDate = currentDate.setDate(currentDate.getDate()- 1); console.log("The yesterday date ="+new Date(yesterdayDate));To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo137.js. This will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo137.js The current date=Fri Jul 31 2020 ... Read More

At first, set the characters and numbers −var storedCharacters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';To generate randomly, use Math.random(). Following is the code −Examplefunction generateRandom3Characters(size) {    var generatedOutput= '';    var storedCharacters =    '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';    var totalCharacterSize = storedCharacters.length;    for ( var index = 0; index < size; index++ ) {       generatedOutput+=storedCharacters.charAt(Math.floor(Math.random() *       totalCharacterSize));    }    return generatedOutput; } console.log(generateRandom3Characters(3));To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo136.js. This will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo136.js lq4

Following is our object −const customerDetails=[    {customerFirstName: "David"},    {customerLastName: "Miller"},    {customerCountryName: "US"},    {customerAge: "29"},    {isMarried: false},    {customerCollegeName: null} ];Let’s assign values to a computed property using slice() along with map().Exampleconst customerDetails=[    {customerFirstName: "David"},    {customerLastName: "Miller"},    {customerCountryName: "US"},    {customerAge: "29"},    {isMarried: false},    {customerCollegeName: null} ]; const newCustomerDetails = customerDetails.slice(2, 4).concat(customerDetails[5]).map(obj=>({    propertyKey: Object.keys(obj)[0],    propertyValue: Object.values(obj)[0] })); console.log(newCustomerDetails);To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo135.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo135.js [    { propertyKey: ... Read More

Let’s say the following is our table − John David Mike Use the following with text() to get last item −$('table tr:last td')Example Live Demo Document John David Mike    var lastValue= $('table tr:last td').text();    console.log("The last value is="+lastValue); To run the above program, save the file name “anyName.html(index.html)” and right click on the file. Select the option “Open with Live Server” in VS Code editor.OutputThis will produce the following output −

Use return statement to assign function to variables. Following is the code −Example Live Demo Document    .demo {       background: skyblue;       height: 20px;       width: 75%;       margin: 10px;       padding: 10px;    } John Smith David Miller Adam Smith    var studentNames = function() {       var names = [];       $(".demo").each(function() {          names.push($(this).data('st'));       });       return names.join();    };    console.log( studentNames() ); To run the above program, save the file name “anyName.html(index.html)” and right click on the file. Select the option “Open with Live Server” in VS Code editor.OutputThis will produce the following output −

To detect the screen resolution, use the concept of window.screen.For width, use the following −window.screen.availWidthFor height −window.screen.availHeightFollowing is the code to detect the screen resolution −Example Live Demo Document    console.log("Available Width="+window.screen.availWidth);    console.log("Available Height="+window.screen.availHeight); To run the above program, save the file name “anyName.html(index.html)” and right click on the file. Select the option “Open with Live Server” in VS Code editor.OutputThis will produce the following output −

The new keyword creates an object in JavaScript. To access values, use the dot notation. Following is the code −Examplefunction newObjectCreation() {    this.firstName = "John"; } var newObject = new newObjectCreation(); newObject.firstName="David"; console.log("The first name="+newObject.firstName);To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo134.jsOutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo134.js The first name=David

To attach event, use document.addEventListener() in JavaScript. Following is the code −Example Live Demo Document    document.addEventListener('click',function(event){       if(event.target && event.target.id== 'buttonSubmit'){          console.log("Event generation on the button click")       }    }); To run the above program, save the file name “anyName.html(index.html)” and right click on the file. Select the option “Open with Live Server” in VS Code editor.OutputThis will produce the following output −After clicking the submit button, the screenshot is as follows −