Yes, you can pass default parameters in nested objects.Following is the code −ExampleFollowing is the code −function callBackFunctionDemo({ cl: { callFunctionName = "callBackFunction", values = 100 } = {} } = {}) {    console.log(callFunctionName);    console.log(values); } //This will print the default value. // 100 callBackFunctionDemo(); //This will print the given value. //500 callBackFunctionDemo({ cl: { values: 500 } });To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo296.js.OutputThis will produce the following output on console −PS C:\Users\Amit\javascript-code> node demo296.js callBackFunction 100 callBackFunction 500

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]); console.log("The original string value=" + values); console.log("String value after preceding the numbers ="); console.log(precedingNumbersInString);To run the above program, you need to use the following command −node fileName.js. Here, my file name is demo295.js.OutputThis will produce the following output on console −PS C:\Users\Amit\javascript-code> node demo295.js The original string value=DDAAVIDMMMILLERRRRR String value ... 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 = {       ...objectValues,        [tempKey]: null    };    console.log(inEachIterationSetOneFieldValueWithNull); }To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo294.js.OutputThis will produce the following output on console −PS C:\Users\Amit\javascript-code> node demo294.js { name1: null, name2: 'David', address1: 'US', address2: 'UK' ... 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');    textBoxNameHTML.addEventListener('change', (e) => {       localStorage.setItem("textBoxValue", e.target.value);    }); 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.OutputThis will produce the following output on console −Now, I ... 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 the code −var studentDetails =    [       [89, "John"],       [78, "John"],       [94, "John"],       [47, "John"],       [33, "John"]    ]; studentDetails.sort((first, second) => second[0] - first[0]) console.log(studentDetails);To run the above program, you need to use the ... Read More

Let’s say the following is our array −var details = [    {       studentName: "John",       studentMarks: [78, 98]    },    {       studentName: "David",       studentMarks: [87, 87]    },    {       studentName: "Bob",       studentMarks: [48, 58]    },    {       studentName: "Sam",       studentMarks: [98, 98]    }, ]We need to remove the duplicate property value i.e. 87 is repeating above. We need to remove it.For this, use the concept of map().ExampleFollowing is the code −var details ... 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 the file name “anyName.html(index.html)”. Right click on the file and select the option “Open with Live Server” in VS Code editor.OutputThis will produce the following output on console −When you click the mouse, the event will generate. The console output is shown below −

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 the above program, you need to use the following command −node fileName.js. Here, my file name is demo291.js.OutputThis will produce the following output on console −PS C:\Users\Amit\javascript-code> node demo291.js The date value is=Tue Jan 12 2021 12:10:20 GMT+0530 (India Standard Time) Only Hours value after incrementing=12Read 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 to use the following command −node fileName.js.Here, my file name is demo290.js.OutputThis will produce the following output on console −PS C:\Users\Amit\javascript-code> node demo290.js { John: 0, David: 1, Mike: 2, Sam: 3, Bob: 4, Adam: 5 }

When we press the escape key, the event generated is detected using the keyup and keydown event handlers. When the escape key is pushed on the keyboard, the event handler runs across the page. Let’s dive into the article for getting better understanding on handling esc keydown on JavaScript popup window. Using keydown event When a key is pushed, the keydown event is triggered. The keydown event is called for all keys, regardless of whether they generate a character value, in contrast to the deprecated keypress event. While keypress shows which character was entered, keydown and keyup events give a ... Read More