Let’s say our original string is the following with repeated letters −var values = "DDAAVIDMMMILLERRRRR";We want to remove the repeated letters and precede letters with numbers. For this, use replace() along with regular expression.ExampleFollowing is the code −var values = "DDAAVIDMMMILLERRRRR"; var precedingNumbersInString = values.replace(/(.)\1+/g, obj => obj.length + obj[0]); ... Read More

For this, use Object.keys() and set one key on each iteration as null using a for loop..ExampleFollowing is the code −var objectValues = {    "name1": "John",    "name2": "David",    "address1": "US",    "address2": "UK" } for (var tempKey of Object.keys(objectValues)) {    var inEachIterationSetOneFieldValueWithNull = {     ... Read More

Use localStorage.setItem(“anyKeyName”, yourValue) to set the value in local storage and if you want to fetch value then you can use localStorage.getItem(“yourKeyName”)ExampleFollowing is the code − Live Demo            Document        var textBoxNameHTML = document.getElementById('txtName'); ... Read More

Let’s say we have the following array −var studentDetails = [    [89, "John"],    [78, "John"],    [94, "John"],    [47, "John"],    [33, "John"] ];And we need to sort the array on the basis of the first item i.e. 89, 78, 94, etc. For this, use sort().ExampleFollowing is ... Read More

Let’s say the following is our array −var details = [    {       studentName: "John",       studentMarks: [78, 98]    },    {       studentName: "David",       studentMarks: [87, 87]    },    {       studentName: "Bob",     ... Read More

For this, use the addEventListener() with mousedown event.ExampleFollowing is the code −            Document    document.addEventListener("mousedown", function () {       console.log("Mouse down event is happening");    }); To run the above program, save ... Read More

At first, set a new Date in JavaScript −var dateValue = new Date("2021-01-12 10:10:20");Use new Date() along with setHours() and getHours() to add time.ExampleFollowing is the code −var dateValue = new Date("2021-01-12 10:10:20"); dateValue.setHours(dateValue.getHours() + 2); console.log("The date value is=" + dateValue.toString()); console.log("Only Hours value after incrementing=" + dateValue.getHours());To run ... Read More

For this, use forEach() along with [] to an associative array.ExampleFollowing is the code −var result = {}; var names = ['John', 'David', 'Mike', 'Sam', 'Bob', 'Adam']; names.forEach((nameObject, counter) => {    var generatedValues = { [nameObject]: counter };    Object.assign(result, generatedValues) }) console.log(result);To run the above program, you need ... Read More

Let’s say the following is our button −Press MeOn filling the below input field, the color of the above button should change −ExampleFollowing is the code − Live Demo            Document           UserName:     ... Read More

If the const is used in a program, and if you try to reassign the value to const variable then an error will arise.Let’s say the following is our const variable −const result = (first, second) => first * second;Now, we will try to reassign a value to the const ... Read More