how to set default parameter in javascript code example

Example 1: javascript default parameters

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

Example 2: javascript default function parameter value

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

Example 3: default value of functin atribute

function say(message='Hi', number=7) {
    console.log(message);
  	console.log(number);
}

say();
// 'Hi'
// 7

Example 4: ES6: Set Default Parameters for Your Functions

const resultDisplayArray = []; 
for(let i = 0; i < result.failure.length; i++) {
resultDisplayArray.push(`<li class="text-warning">${result.failure[i]}</li>`); 
}