Getting JavaScript Object key List
Use the “Object.keys()” method or the “for-in” loop with the “push()” method to get the list of keys of an object in JavaScript.
How to Create If Statement One-Liners Using JavaScript
To create a one-liner “if” statement, use the “ternary” operator. It is commonly used as a shortcut for if-else statements.
How to Initialize an Array’s Length in JavaScript
To initialize an array’s length, use the “Array constructor” with a single argument, which is the length of the array you want to create.
How to Find the Factorial of a Number in JavaScript
To find the factorial of a number, two methods can be utilized, the “Iterative Method” and the second is “Recursive Method”.
JavaScript Get Element by Name – HTML
To get the element by name, use the JavaScript prebuilt methods, such as “getElementsByName()” or the “querySelectorAll()”.
Array.findIndex() in ES6
Array.findIndex() JavaScript method introduced in ES6 is used to return the index of an initial array element that satisfies the added condition.
How to Stop a JavaScript for Loop
Use the “break” statement to stop the “for” loop in JavaScript. It can be used to stop “for”, “for…of”, and “for…in” loops but not used in “forEach” loop.
How to Write isNumber() in JavaScript
To write the “isNumber()” function in JavaScript, use the “typeof” operator or the JavaScript library called “underscore.js”.
How to Validate Radio Button Using JavaScript
To validate a radio button using JavaScript, use the “checked” property of the radio button element to check whether it is selected.
How to Blink Screen in JavaScript
Blinking the entire screen can be done using JavaScript and the “setInterval” function to repeatedly change the page’s background color.
Convert Array to JSON – JavaScript
To convert the array into a JSON object, apply the JSON.stringify() method in combination with the JSON.parse() method or the Object.assign() method.
JavaScript Regular Expression Email Validation
Use the general regular expression or regex pattern “/[a-z0-9]+@[a-z]+\.[a-z]{2,3}/” to validate the email in JavaScript with the “match()” method.
JavaScript Check if Variable Exists (Defined/Initialized)
To check if variable exists (defined/initialized), use “typeof” operator because it does not generate a “ReferenceError” if variable has not yet been declared.
JavaScript – Validation, Numbers Only
Use the “regular expression” as regex patterns or the “isNaN()” method to validate the fields in a form to get only the numbers.
JavaScript – Get Portion of URL Path
To get the portion of the URL path in JavaScript, apply the “location.host” and “pathname” properties or the “slice()” and “split()” methods.
How to Terminate the Script in JavaScript
To terminate the script in JavaScript, use the “return” statement, “debugger” command, or “throw an error” while in Node.js, use “abort()” or “exit()” methods.
How to Create an Array Containing 1…N
Use “for” loop with “push()” method, “Array.from()” method, or “Spread operator” with the “key()” and the “map()” methods to create an array containing 1 to N.
Generating Random Whole Numbers in JavaScript in a Specific Range
To generate random whole numbers in JavaScript within the specific range, use the “random()” method with the combination of the “floor()” method.
Getting a Random Value From a JavaScript Array
To get a random value from a JavaScript array, use the JavaScript predefined “Math.random()” method with the “Math.floor()”.
Get Loop Counter/Index Using for…of Syntax in JavaScript
To get the loop counter or index using the for…of syntax in JavaScript, use the array.entries() method with for…of loop.