Default function parameters

The default function parameters in ES6, gives us the ability to initialize the function arguments with default values in case if they are undefined. For example,

function mult(a, b) {
  b = typeof b !== 'undefined' ?  b : 1;
  return a*b;
}
mult(5); // 5

function multiply(a, b = 1) {
  return a*b;
}
mult(5); // 5

Also Read:

1. Array filterUntil function implementation for javascript
2. pseudo elements vs pseudo classes
3. Applying floats to inline elements
4. box-sizing
5. Generators and Yield in es6