This is not a real life scenario. I am trying to learn more about strings in js, and came across the following:
var name = new String('sann');
console.log('type of name=' ,typeof name);
// returns object in nodejs but string in browser
console.log('name instanceof String' ,name instanceof String)
// returns true in nodejs but false in browser
NodeJS output was in line with my expectation, I am puzzled by the browser output.
What is the reason for this difference in behaviour ?
Both are right.
The spec says (emphasis mine):
The String constructor is the %String% intrinsic object and the initial value of the String property of the global object. When called as a constructor it creates and initializes a new String object. When String is called as a function rather than as a constructor, it performs a type conversion.
So new String(value) returns a String object rather that a primitive.
In a browser anyway, the global window object has a property called name, whose setter automatically converts the supplied value into a string.
The same snippet, if wrapped into a function call, reports name to be of type object, as expected.
(() =>
{
var name = new String('sann');
console.log('type of name', typeof name);
console.log('name instanceof String', name instanceof String);
}
)();In Node.js the global object does not have that property, and so name is treated as a plain value.
Your problem is about window object in the browser, which does not exist in nodejs. You can also read this answer which explains your problem: https://stackoverflow.com/a/36408348/3554534
