js function parameter default code example

Example 1: javascript constructor default parameter

function greet(name, greeting, message = greeting + ' ' + name) {
  return [name, greeting, message]
}

greet('David', 'Hi')                     // ["David", "Hi", "Hi David"]
greet('David', 'Hi', 'Happy Birthday!')  // ["David", "Hi", "Happy Birthday!"]

Example 2: javascript default parameters

function multiply(a, b = 1) {
  return a * b;
}

Example 3: js default parameter

function greeting (name = 'stranger') {
  console.log(`Hello, ${name}!`)
}

greeting('Nick') // Output: Hello, Nick!
greeting() // Output: Hello, stranger!

Example 4: variable defaults javascript es6

let variableToSet = checkedValue || defaultValue;

Example 5: ES6: Set Default Parameters for Your Functions

const increment = (number, value = 1) => number + value;