default value javascript function code example

Example 1: default in javascript

const greet = (message = 'Hello World!') => console.log(message);

greet(); // prints 'Hello World!'
greet('Hello! Does this answer your question?') // prints 'Hello! Does this answer your question?'

Example 2: js default parameter

function read_file(file, default_param = false) {
  // Code
}

Example 3: javascript default function parameter value

function multiply(a, b) {
  b = (typeof b !== 'undefined') ?  b : 1
  return a * b
}

Example 4: variable defaults javascript es6

let variableToSet = checkedValue || defaultValue;