Question

This question is a spin-off of [] is an instance of Array but "" isn't of String

Given that

"" instanceof String; /* false */
String() instanceof String; /* false */
new String() instanceof String; /* true */

and

typeof "" === "string"; /* true */
typeof String() === "string"; /* true */
typeof new String() === "string"; /* false */

Then, if I have a variable abc and I want to know if it’s a string, I can do

if(typeof abc === "string" || abc instanceof String){
    // do something
}

Is there a simpler, shorter and native way of doing this, or must I create my own function?

function isStr(s){
    return typeof s === "string" || s instanceof String;
}
if(isStr(abc)){
    // do something
}

Answer 1

I think Object.prototype.toString.call(a) === "[object String]" is the shortest/nativest way of doing this