change variable value in function javascript code example

Example 1: how to change a variables value in javascript

var variable = 10;

function start() {
  variable = 20;
}
console.log(variable + 20);

// Answer will be 40 since the variable was changed in the function

Example 2: change variable inside function js

var a = 10;

myFunction();

function myFunction(){
   a = 20;
}

alert("Value of 'a' outside the function " + a); //outputs 20