let a = 6;
let b = 9;
let c = a * b;
// stops the execution
debugger;
console.log(c);
// Stop Being Broke and install node.js or add js file to a HTML then open it
// in a tab.
Or just: https://jsbin.com/
If you want to dubug the code
use this only "dubugger();" in the javascript code where you want to debug step by step