To make first letter of a string uppercase, use toUpperCase() in JavaScript. With that, we will use charAt(0) since we need to only capitalize the 1st letter.Examplefunction replaceWithTheCapitalLetter(values){    return values.charAt(0).toUpperCase() + values.slice(1); } var word="javascript" console.log(replaceWithTheCapitalLetter(word));To run the above program, you need to use the following command −node fileName.js.Here, my file name is demo167.js.OutputThis will produce the following output −PS C:\Users\Amit\javascript-code> node demo167.js Javascript

To avoid using variable name as a literal, use square brackets. Following is the code −Examplevar name = "David" var putTheAllData = [] putTheAllData.push( { name: "The name is name will remain same" } ) putTheAllData.push( { [name]: "The name is David will be changed [name]"} ) console.log(putTheAllData);To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo166.js. This will produce the following output −PS C:\Users\Amit\javascript-code> node demo166.js [    { name: 'The name is name will remain same' },    { David: 'The name is David will be changed [name]' } ]

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

The primitive data types are number, string, boolean, float etc. The non-primitive data types (Reference Type) are Array, Object etc.Examplevar number=10; var stringValue="John"; var booleanValue=true; var obj={}; var newArray=new Array(); console.log("The data type is="+typeof number); console.log("The data type is="+typeof stringValue); console.log("The data type is="+typeof booleanValue); console.log("The data type is="+typeof obj); console.log("The data type is="+typeof newArray);To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo162.js. This will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo162.js The data type is=number The data type is=string The data type is=boolean The data type is=object The ... Read More

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 −

To extract hostname from URL string, use split() function. Following is the code −Examplefunction gettingTheHostNameFromURL(websiteURL) {    var getTheHostName;    if (websiteURL.indexOf("//") > -1) {       getTheHostName = websiteURL.split('/')[2];    } else {       getTheHostName = websiteURL.split('/')[0];    }    getTheHostName = getTheHostName.split(':')[0];    getTheHostName = getTheHostName.split('?')[0];    return getTheHostName; } var websiteURL="https://www.tutorialspoint.com/java/index.htm";var websiteURL1="https://www.tutorix.com/about_us.htm"; var websiteURL2="https://www.tutorialspoint.com/execute_python_online.php"; console.log(gettingTheHostNameFromURL(websiteURL)) console.log(gettingTheHostNameFromURL(websiteURL1)) console.log(gettingTheHostNameFromURL(websiteURL2))To run the above program, you need to use the following command −node fileName.js.OutputHere, my file name is demo161.js. This will produce the following output −PS C:\Users\Amit\JavaScript-code> node demo161.js www.tutorialspoint.com www.tutorix.com www.tutorialspoint.comRead More

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