how to addd two number in javascript code example

Example 1: how to add two numbers in javascript

let a = 4;
let b = 5;
document.write(a + b);

Example 2: to add 2 numbers using function in javascript

// Prints the sum of 2 float numbers 
function addition(number_1, number_2)
{
  int sum = number_1 + number_2
document.write(sum)
}

var number_1 = parseFloat(prompt("First Number"));
var number_2 = parseFloat(prompt("Second Number"));
addition(number_1, number_2);