Performance of Google chrome vs nodejs (v8)?

Question

Example

     console.time("Test");
     for(var i=0; i         


        

Answer 1

Its Due To SCOPE in JavaScript

In Browser console code without scope : Takes lots of time : Test: 1154.19ms

below code will be kept in heavily populated window object which will take time to resolve;

 console.time("Test");
 for(var i=0; i <2500000; i +=1 ){
         // loop around
 }
 console.timeEnd("Test");

In Browser console code with scope : Takes less time Test: 3.06ms

below code will be kept inside JavaScript scope and scope will be almost empty so less time

function rocket(){
    console.time("Test");
     for(var i=0; i <2500000; i +=1 ){
             // loop around
     }
     console.timeEnd("Test");
}
rocket()

In Nodejs REPL : code without scope : Test: 14ms

Unexpected But nodejs most outer scope contains some bunch of variables

 console.time("Test");
 for(var i=0; i <2500000; i +=1 ){
         // loop around
 }
 console.timeEnd("Test");

In Nodejs REPL : code with scope : Test: 2ms

below code will be kept inside JavaScript scope and scope will be almost empty so less time

function rocket(){
    console.time("Test");
     for(var i=0; i <2500000; i +=1 ){
             // loop around
     }
     console.timeEnd("Test");
}
rocket()

Conclusion : Its all due to SCOPE and SCOPING in JavaScript is done by functions

Means if you create new function ,the place inside curly brackets {} is called as SCOPE and it will be empty initially, and if you create variable in this scope it will take no time to execute