Default Parameters
It is used to give the default values to the arguments, if no parameter is provided in the function call.
Syntax:
function fnName(param1 = defaultValue1, ..., paramN = defaultValueN) {
. . .
}
Example: In the below example, the first function gives result 7 whereas the second function call will be “undefined” as we did not pass any second argument.
Javascript
function add(a, b) { return a + b } console.log(add(5, 2)); // 7 console.log(add(5)); // NaN |
7 NaN
JS 2015 or ECMAScript 6 (ES6)
JS 2015 (ES6) also known as ECMAScript 6 (ES6), ECMAScript 6 (ES6) is a significant update to JavaScript, introducing arrow functions, classes, template literals, let and const for variable declaration, enhanced object literals, destructuring, and more modern features for better code organization and readability.