Does javascript have a method to replace part of a string without creating a new string?

Question

var str = \"This is a string\";
var thing = str.replace(\"string\",\"thing\");

console.log( str )
>> \"This is a string\" 

console.log( thing )
>> \"Th         


        

Answer 1

There is a reason why strings are immutable. As Javascript use call-by-sharing technic, mutable string would be a problem in this case :

function thinger(str) {
    return str.replace("string", "thing");
}

var str = "This is a str";
var thing = thinger(str);

In this situation you want your string to be passed by value, but it is not. If str was mutable, thinger would change str, that would be a really strange effect.