Javascript Articles - Page 296 of 534

For this, use push() along with forEach(). Following is the code −Examplevar details = [{name:"John"},{name:"David"}] var addObject = ["Mike","Sam"]; addObject.forEach( obj1 => {    if(!details.find( obj2 => obj2===obj1 ))       details.push({name:obj1}) }) console.log(details);To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo165.js.OutputThis will produce the following output −PS C:\Users\Amit\javascript-code> node demo165.js [    { name: 'John' },    { name: 'David' },    { name: 'Mike' },    { name: 'Sam' } ]

Let’s say the following are our strings with commas −"My Favorite subject is, " "My Favorite subject is, and teacher name is Adam Smith" "My Favorite subject is, and got the marks 89"To replace commas, use replace and in that, use Regular Expression. Following is the code −Exampleconst makingRegularExpression = /, (?=[^, ]*$)/; replaceComma("My Favorite subject is, "); replaceComma("My Favorite subject is, and teacher name is Adam Smith"); replaceComma("My Favorite subject is, and got the marks 89"); function replaceComma(values){    console.log(values, " ==== replaced by JavaScript ==== ", values.replace(ma    kingRegularExpression, " JavaScript")); }To run the above program, you need ... Read More

Let’s say the following is our string with name −var studentFullName="John Smith";Use split() to split the first name and last name. Following is the code −Examplevar studentFullName="John Smith"; var details=[] var details=studentFullName.split(' '); console.log("StudentFirstName="+details[0]) console.log("StudentLastName="+details[1]);To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo163.js. This will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo163.js StudentFirstName=John StudentLastName=Smith

For ENTER key press event, you can call a function on −onkeypress=”yourFunctionName”Use the ENTER’s keycode 13.Example Live Demo Document    function enterKeyPressed(event) {       if (event.keyCode == 13) {          console.log("Enter key is pressed");          return true;       } else {          return false;       }    } 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 −On pressing ENTER key, the following output is visible on console −

For this, use . Since you want to type in it, do not forget to set as −contenteditable="true"Example Live Demo Document    span{       border: solid 2px skyblue;    }    div{       max-width: 500px;    } John Smith 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 −

To find the index of a two-dimensional array of objects, use two for loops, one for row and another for column. Following is the code −Examplefunction matrixIndexed(details, name) {    var r;    var c;    for (r = 0; r < details.length; ++r) {       const nsDetails = details[r];       for (c = 0; c < nsDetails.length; ++c) {          const tempObject = nsDetails[c];          if (tempObject.studentName === name) {             return { r, c};          }       } ... Read More

To get sequence number in loops, use the forEach() loop. Following is the code −Examplelet studentDetails = [    {       id: 101, details: [{name: 'John'}, {name: 'David'},{name: 'Bob'}]},       {id:102, details: [{name:'Carol'},{name:'David'},       {name:'Mike'}]    } ]; var counter = 1; studentDetails.forEach(function(k){    k.details.forEach(function(f) {          console.log(counter++);       }    ); });To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo159.js. This will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo159.js 1 2 3 4 5 6

Let’s say the following is our array of objects with duplicates −var studentDetails=[    {studentId:101},    {studentId:104},    {studentId:106},    {studentId:104},    {studentId:110},    {studentId:106}, ]Use the concept of set to remove duplicates as in the below code −Examplevar studentDetails=[    {studentId:101},    {studentId:104},    {studentId:106},    {studentId:104},    {studentId:110},    {studentId:106}, ] const distinctValues = new Set const withoutDuplicate = [] for (const tempObj of studentDetails) {    if (!distinctValues.has(tempObj.studentId)) {       distinctValues.add(tempObj.studentId)       withoutDuplicate.push(tempObj)    } } console.log(withoutDuplicate);To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name ... Read More

For this, use Object.assign(). Following is the code −Exampleconst details = {john:{'studentName':'John'}, david:{'studentName':'David'}, mike:{'studen tName':'Mike'}, bob:{'studentName':'Bob'}, carol:{'studentName':'Carol'}}, join_values = ['David', 'Carol'],    output = Object.assign(       {},       ...Object       .keys(details)       .map(key =>       ({[key]: {          ...details[key],          lastName: join_values.includes(details[key].studentName) ?          'Miller' : 'Smith'    }}))) console.log(output)To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo157.js. This will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo157.js {    john: ... Read More

We will be creating two buttons, one for Increment and another Decrement −On clicking Increment (+), user will be able to increment the number in input type numberOn clicking Decrement (-), user will be able to decrement the number in input type numberExample Live Demo Document + -    function increment() {       document.getElementById('demoInput').stepUp();    }    function decrement() {       document.getElementById('demoInput').stepDown();    } To run the above program, save the file name “anyName.html(index.html)” and right click on the file. Select the option ... Read More