JavaScript strict type checking fails -

i checking 3 strings equality;

var str1 = "hello world!"; var str2 = "hello \     world!"; var str3 = "hello" + " world!"; //console.log(str1===str2);//true // console.log(str2===str3);//true console.log(str1 === str2 === str3); //false 

how can check scenario want compare 3 variables?

your question isn't totally clear me.

 assuming question how compare equality of 3 strings:

with

console.log(str1 === str2 === str3); 

you're checking

(str1 === str2) === str3 

(yes, associativity left right here)

that is, you're comparing boolean string.

what want is

(str1 === str2) && (str2 === str3) 

assuming question how compare strings not caring numbers , types of spaces (see note below):

then best normalize strings using function like

function normalize(str){     return str.replace(/\s+/g,' '); } 

and can define function comparing strings:

function allequals(strs) {    var p;    (var i=0; i<arguments.length; i++) {        if (typeof arguments[i] !== "string") return false;        var s = arguments[i].replace(/\s+/g, ' ');        if (p !== undefined && s!==p) return false;        p = s;    }    return true; }  console.log(allequals(str1, str2, str3)); 

note: multi-line string literals painful. strings different:

var str2 = "hello \     world!"; var str4 = "hello \ world!";