How to check if string has same content

I'm not sure what exactly you want to do but I think that localCompare() method is the best choice. It returns -1 if the reference string is sorted before the compareString, 0 if are the same and 1 if the reference string is sorted after the compareString. Syntax: string.localeCompare(compareString)

var str1 = "cd";
var str2 = "ab";
var n = str1.localeCompare(str2);
1 // str1 is sorted after str2

Keep in mind that strings are compared in sort order and this methods depends on the language settings of the browser.

In JavaScript you can easly compare two stings with == operator (you should check it out here) Although you should be carefull because == operator checks for lower/uppercase Example:

var first =  "a";
var second = "b";
var third = "a";
var fourth = "A";

first == second; //  false
first == third; // true
first == fourth; // false
first.toUpperCase() == fourth; // true

So if you want to compare the content, you should use toLowerCase or toUpperCase ;) (MDN toUpperCase)

I hope it helped, cheers! :)