For this, use map() along with join(‘’).Then ‘’ is for new line. Following is the code −ExamplestudentDetails = [    [101, 'John', 'JavaScript'],    [102, 'Bob', 'MySQL'] ]; var studentFormat = '||Id||Name||subjName||'; var seperate = ''; seperate = seperate + studentDetails.map(obj => `|${obj.join('|')}|`).join(''); studentFormat = studentFormat + seperate; console.log(studentFormat);To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo112.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo112.js ||Id||Name||subjName|| |101|John|JavaScript| |102|Bob|MySQL|

Let’s say the following is our current array −var listOfNames=["John", "Mike", "Sam", "Carol"];Use JSON.parse(JSON.stringify()) to create new array and set values from the old array above.Examplefunction createNewArray(listOfNames) {    return JSON.parse(JSON.stringify(listOfNames)); } var listOfNames=["John", "Mike", "Sam", "Carol"]; var namesArray = listOfNames.slice(); console.log("The new Array="); console.log(namesArray);To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo111.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo111.js The new Array= [ 'John', 'Mike', 'Sam', 'Carol' ]Read More

Let’s say, we are matching the current date and time with the business hours. We need to display whether the office is closed or open right now on the basis of current time.Get the hours from the current date and can use the ternary operator for close and open. Following is the code −Example Live Demo Document    const gettingHours = new Date().getHours()    const actualHours = (gettingHours >= 10 && gettingHours < 18) ? 'Open' : 'Closed';    document.querySelector('.closeOrOpened').innerHTML = actualHours; To run the above program, save ... Read More

The recursive function calls itself with some base condition. Let’s say the following is our array with marks −var listOfMarks=[56, 78, 90, 94, 91, 82, 77];Following is the code to get the count of array elements −Examplefunction countNumberOfElementsUsingRecursive(listOfMarks) {    if (listOfMarks.length == 0) {       return 0;    }    return 1 +    countNumberOfElementsUsingRecursive(listOfMarks.slice(1)); } var listOfMarks=[56, 78, 90, 94, 91, 82, 77]; console.log("The array="); console.log(listOfMarks); var numberOfElements=countNumberOfElementsUsingRecursive(listOfMarks); console.log("The Number of elements = "+numberOfElements);To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo110.js.OutputThis will produce the following ... Read More

Let’s say, first, we will set the start and end range and call the function:console.log(getRandomValueBetweenTwoValues(400, 480))We have passed start value 400 and end value 480. Let’s get the random value with Math.random() in JavaScript −Examplefunction getRandomValueBetweenTwoValues(startRange, endRange) {    return Math.floor(Math.random() * (endRange - startRange + 1) + startRange); } console.log(getRandomValueBetweenTwoValues(400, 480))To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo109.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo109.js 401

To check whitespace in a string, use the concept of indexOf(‘ ’). Following is the code −Examplefunction stringHasTheWhiteSpaceOrNot(value){    return value.indexOf(' ') >= 0; } var whiteSpace=stringHasTheWhiteSpaceOrNot("MyNameis John");    if(whiteSpace==true){       console.log("The string has whitespace");    } else {       console.log("The string does not have whitespace"); }To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo108.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo108.js The string has whitespace

You can use match() with passing the variable name. The syntax is as follows −console.log(yourVariableName.match(yourMatchingVariableName));Examplevar senetence = 'My Name is John'; console.log("The actual value="); console.log(senetence); var matchWord = 'John'; console.log("The matching value="); console.log(matchWord); var matchRegularExpression = new RegExp(matchWord, 'g' ); console.log(senetence.match(matchWord));To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo107.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo107.js The actual value= My Name is John The matching value= JohnRead More

Let’s say we have the following records of studentId and studentName and want to check a specific student name −const studentDetails= [    {       studentId:101,       studentName:"John"    },    {       studentId:102,       studentName:"David"    },    {       studentId:103,       studentName:"Carol"    } ]Create a custom function to find by name. Following is the code −Exampleconst studentDetails= [    {       studentId:101,       studentName:"John"    },    {       studentId:102,       studentName:"David"    },    {       studentId:103,       studentName:"Carol"    } ] function findByName(name){    var flag=true;    for(var i=0;i node demo106.js The name found=David

Here’s an example with two loops, outer and inner −Examplelet demoForLoop = ()=>{    for(var outer=1;outer

Let’s say the following is our HTML button −Click the button to add the input into the belowText BoxUse document.getElementById() to add a text in on button click. Following is the code −Example Live Demo Document Click the button to add the input into the below Text Box  document.getElementById("clickButton").addEventListener("click", () =>{ document.getElementById("readTheInput").value += "JavaScript";  }); 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 ... Read More