Javascript Articles - Page 340 of 607

You need to use currentDate with the help of new Date().getDate(). The syntax is as follows −var anyVariableName= yourCurrentDate - yourSubstractDateOfCurrentMonth;Examplevar currentDate=new Date().getDate(); var substractDate=new Date("2020-07-01").getDate(); const numberOfDaysInCurrentMonthOnly = currentDate-substractDate; console.log(numberOfDaysInCurrentMonthOnly);NoteToday’s date is - 28-07-2020To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo129.jsPS C:\Users\Amit\JavaScript-code> node demo129.js 27

An alert in JavaScript is a dialog box that is displayed to the user when some important information or warnings needs to be notified. It may contain a message along with OK button. When you click on the OK button, it will dismiss the dialog. Clicking a button triggers an event handler which invoke a function that instructs the browser to display a dialog with a message. In this article, we will explore a few ways to get an alert to appear when user click on a button. For example, click on the button given below to get an ... Read More

Let’s say, we have subject records with the time when we are planning to study them −const scheduleDetails = [    { subjectName: 'JavaScript', studyTime: '5 PM - 11 PM' },    { subjectName: 'MySQL', studyTime: '12 AM - 4PM' } ]Here is how we can use the map(). Following is the code −Exampleconst scheduleDetails = [    { subjectName: 'JavaScript', studyTime: '5 PM - 11 PM' },    { subjectName: 'MySQL', studyTime: '12 AM - 4PM' } ] function timeToReadSubjectName(scheduleDetails) {    var currentTime = new Date().getHours();    let result = '';    scheduleDetails.map(obj => {       ... Read More

To format HSON string in JavaScript, use JSON.stringify() with some parameters. Following is the code −Examplevar details = {    studentId: 101,    studentFirstName: 'David',    studentLastName: 'Miller',    studentAge:21,    subjectDetails: {       subjectId: 'JavaScript_101',       subjectName: 'Introduction to JavaScript',    } }; console.log("Not Pretty JSON Format=") console.log(JSON.stringify(details)); console.log("Pretty JSON Format=") console.log(JSON.stringify(details, null, 3));To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo127.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo127.js Not Pretty JSON Format= {"studentId":101, "studentFirstName":"David", "studentLastName":"Miller", "studentAge":21, "subj ectDetails":{"subjectId":"JavaScript_101", "subjectName":"Introduction to JavaScript"}} Pretty ... Read More

To check for consecutive numbers like 100, 101, 102, etc., use the concept of reduce(). TRUE would be returned for consecutive numbers, else false is the return value.Exampleconst sequceIsConsecutive = (obj) => Boolean(obj.reduce((output, lastest) => (output ? (Number(output.number) + 1=== Number(lastest.number) ? lastest : false) : false))); console.log("Is Consecutive="+sequceIsConsecutive ([{ number: '100' }, {number: '101'} ,{number: '102' }])); console.log("Is Consecutive="+sequceIsConsecutive([{ number: '100' }, {number: '102'} ,{number: '104' }]));To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo126.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo126.js Is Consecutive=true Is Consecutive=falseRead More

Following is our object −var customerDetails ={    "customerFirstName":"David",    "customerLastName":"Miller",    "customerAge":21,    "customerCountryName":"US" };Now, create a new array and use push() function. Following is the code −Examplevar customerDetails ={    "customerFirstName":"David",    "customerLastName":"Miller",    "customerAge":21,    "customerCountryName":"US" }; var customerObjectToArray = []; customerObjectToArray.push(customerDetails); console.log(customerObjectToArray);To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo125.js.OutputThis will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo125.js [    {       customerFirstName: 'David',       customerLastName: 'Miller',       customerAge: 21,       customerCountryName: 'US'    } ]

Let’s say the following is our file name −var actualJavaScriptFileName = "demo.js";Following is the word to be inserted before the dot extension −var addValueBetweenFileNameAndExtensions = "programming";At first, you need to split() the file name on the basis of dot(.) and then to insert a character, you can use the concept of template variables. Following is the code −Examplevar addValueBetweenFileNameAndExtensions = "programming"; var actualJavaScriptFileName = "demo.js"; console.log("The actual File name="+actualJavaScriptFileName); var [fileName, fileExtension] = actualJavaScriptFileName.split('.'); console.log("After adding into the file name="); console.log(`${fileName}- ${addValueBetweenFileNameAndExtensions}.${fileExtension}`)To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo124.js. ... Read More

To convert string type value to array type, use the parse() method. Following is the code −Examplevar customerDetails='[    {"name": "John", "countryName": "US"},    {"name": "David", "countryName": "AUS"},    {"name": "Bob", "countryName": "UK"} ]'; console.log("The actual value="+customerDetails); var convertStringToArray=JSON.parse(customerDetails); console.log("After converting string to array objects="); console.log(convertStringToArray);To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo123.js. This will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo123.js The actual value=[{"name": "John", "countryName": "US"}, {"name": "David", "countryName": "AUS"}, {"name": "Bob", "countryName": "UK"}] After converting string to array objects=[    { name: 'John', countryName: 'US' ... Read More