JavaScript

To store an array as a value in a JavaScript Map, you can create a new Map and then use the set() method to add key-value pairs, where the value is an array. const mainMap = new Map(); mainMap.set(‘key1’, [1, 2, 3]); mainMap.set(‘key2’, [‘a’, ‘b’, ‘c’]); console.log(mainMap.get(‘key1’)); console.log(mainMap.get(‘key2’)); Output [ 1, 2, 3 ] [ … Read more

To filter an array with multiple conditions in JavaScript, you can use the “Array.prototype.filter()” method. You can combine multiple conditions using logical operators such as “&& (AND)” or “|| (OR)” in the callback function provided by the filter() method. Syntax const filteredArray = originalArray.filter(item => condition1 && condition2 && … && conditionN); Example const items … Read more

To add a class to a given element in JavaScript, you can use the “element.classList.add()” method. The add() is a built-in JavaScript method of the DOMTokenList Interface for modern browsers that adds the given token to the list. Syntax element.classList.add(“your_class_name”); You can also add multiple classes to your HTML elements. element.classList.add(“class_1”, “class_2”, “class_3”) Example The … Read more

To get the current date and time in UTC, you can use the “Date object’s getUTC*()” method in JavaScript. const now = new Date(); const year = now.getUTCFullYear(); const month = now.getUTCMonth() + 1; const day = now.getUTCDate(); const hours = now.getUTCHours(); const minutes = now.getUTCMinutes(); const seconds = now.getUTCSeconds(); const milliseconds = now.getUTCMilliseconds(); console.log(`${year}-${month}-${day} ${hours}:${minutes}:${seconds}.${milliseconds}`); … Read more

To fix the unexpected reserved word ‘await’ error in JavaScript, declare your function “async”. The error “unexpected reserved word await” occurs when we use the ‘await’ keyword inside a not marked as async function. If we need to use the ‘await’, we should make the function ‘async’. function getString() { // not marked as async function … Read more

To convert a String to an Object in JavaScript, you can “use the JSON.parse()” method. The JSON.parse() method is “used to parse a string and return an object.” JavaScript JSON.parse() The JSON.parse() method parses a string and returns an object. The JSON.parse() function takes one required and one optional parameter to perform some operation and … Read more

To write a file in JavaScript, you can use the “writeFile()” method of the fs(File-System) module. The fs.writeFile() is a Node.js method used to write the specified data to a file asynchronously. By default, the file would be replaced if it existed. Syntax writeFile(Path, Data, callback) Parameters The writeFile() method accepts three parameters: path, data, and … Read more

To convert a URL to a String in JavaScript, you can use either the “toString()” or “encodeURI()” methods. Method 1: Using the toSting() function The toString() is a built-in JavaScript method “used to convert the whole URL to a string.” The URL.toString() is a stringifier method that returns a USVString containing the whole URL. Even … Read more