For this, you can use the concept of focus(). Following is the code −Example Live Demo Document Submit    const submitButton = document.getElementById('submitBtn');    submitButton.addEventListener('click', () => {       console.log('Submitting information to the server.....');    })    const txtInput = document.getElementById('txtInput');    txtInput.addEventListener('blur', () => {       console.log('Enter the new value into the text box......');       txtInput.focus();    });    txtInput.focus(); To run the above program, save the file name “anyName.html(index.html)” and right click on the file. Select the option “Open ... Read More

To filter null from an array and display only non-null values instead, use filter(). Following is the code −Examplevar names=[null, "John", null, "David", "", "Mike", null, undefined, "Bob", "Adam", null, null]; console.log("Before filter null="); console.log(names); var filterNull=[]; filterNullValues=names.filter(obj=>obj); console.log("After filtering the null values="); console.log(filterNullValues);To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo148.js. This will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo148.js Before filter null=[    null, 'John',    null, 'David',    '', 'Mike',    null, undefined,    'Bob', 'Adam',    null, null ] After filtering the null values= [ ... Read More

Let’s say the following is our object −const subjectDetails ={    102:"Java",    105:"JavaScript",    104:"MongoDB",    101:"MySQL" };Use sort() method to retrieve object’s entry in order −const orderSubjects = Object.fromEntries(Object.keys(subjectDetails).sort().map((k) => {    return [k, subjectDetails[k]]; }));Exampleconst subjectDetails ={    102:"Java",    105:"JavaScript",    104:"MongoDB",    101:"MySQL" }; const orderSubjects = Object.fromEntries(Object.keys(subjectDetails).sort().map((k) => {    return [k, subjectDetails[k]]; })); console.log(orderSubjects);To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo146.js. This will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo146.js{    '101': 'MySQL',    '102': 'Java',    '104': 'MongoDB',    '105': ... Read More

To print JSON nested object in JavaScript, use for loop along with JSON.parse(). Following is the code −Examplevar details = [    {       "studentId": 101,       "studentName": "John",       "countryName": "US",       "subjectDetails": "{\"0\":\"JavaScript\",\"1\":\"David\"}"    },    {       "studentId": 102,       "studentName": "Bob",       "countryName": "UK",       "subjectDetails": "{\"0\":\"Java\",\"1\":\"Carol\"}"    },    {       "studentId": 103,       "studentName": "Mike",       "countryName": "AUS",       "subjectDetails": "{\"0\":\"MongoDB\",\"1\":\"Adam\"}"    } ] for (const detailsObject of details) {    const subjectDetailsObject =    JSON.parse(detailsObject.subjectDetails);    console.log(subjectDetailsObject[0]); }To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo145.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo145.js JavaScript Java MongoDB

To get HTML form values, use the value property. Let’s say the following is our input type −We need to display the above value “My name is John Smith” on console.Example Live Demo Document    var originalvalue = document.getElementById("getValues").value;    console.log("The value in the text box is ="+originalvalue); 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 −

For this, use the concept of reduce(). Following is the code −Exampleconst subjectDetails = [    {       subjectId: '101',       subjectName: 'JavaScript'    },    {       subjectId: '102',       subjectName: 'Java'    },    {       subjectId: '103',       subjectName: 'JavaScript'    } ]; console.log([...subjectDetails.reduce((obj1, obj2) => {    if (obj1.has(obj2.subjectName)){       obj1.get(obj2.subjectName).frequency++;    } else {       obj1.set(obj2.subjectName, { subjectName: obj2.subjectName,       frequency: 1 });    }    return obj1; }, new Map()).values()]);To run the above program, you need ... Read More

To create, use add() method, whereas to delete created and appended element, you can use remove(). Following is the code −Example Live Demo Document Add A New Name AddName    var givenName = document.querySelector('#name')    var btnClass = document.querySelector('#addNameButton')    var listOfName = document.querySelector('#listOfName')    btnClass.addEventListener('click', () => {       var actualName = givenName.value       if (actualName.length != 0) {          var createAnHTMLList = `${actualName}Remove Name`          listOfName.innerHTML += ... Read More

Let’s get the current date first −var currentDate = new Date(); console.log("The current date is as follows="+currentDate);Now, let us remove seconds/ milliseconds by setting them to 0 using setSeconds() −currentDate.setSeconds(0, 0);Convert to ISO String using toISOString() −currentDate.toISOString()Let us now see the complete code with output −Examplevar currentDate = new Date(); console.log("The current date is as follows="+currentDate); currentDate.setSeconds(0, 0); console.log("After removing seconds from date, the new date is as follows="); console.log(currentDate.toISOString());To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo143.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo143.js The current date ... Read More

To toggle hide class only on selected div, you need to set event on click button. Let’s say you need to hide a specific div on the click of + sign.To get font + or - icon, you need to link font-awesome −Following is the code to toggle hide class on clicking + sign −Example Live Demo Document .hideDiv { display: none; } Customer 1 John US Customer 2 David AUS $(".fa-plus").on("click", function(){ $(this).parent().siblings('.secondDetails').toggleClass("hideDiv"); }); To run ... Read More

Let’s say the following are our arrays −var firstNamesArray=["John", "David", "Bob", "Sam", "Carol"]; var secondNamesArray=["Mike", "Carol", "Adam", "David"];The easiest way to perform array intersection is by using filter() along with includes(). Following is the code −Examplevar firstNamesArray=["John", "David", "Bob", "Sam", "Carol"]; var secondNamesArray=["Mike", "Carol", "Adam", "David"]; var intersectionOfArray=[]; intersectionOfArray=firstNamesArray.filter(v => secondNamesArray.includes(v)); console.log("Intersection of two array="); console.log(intersectionOfArray);To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo141.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo141.js Intersection of two array= [ 'David', 'Carol' ]Read More