Could anyone explain me why the result of this question is b? Aren't a and b identical (same type and same value)?

Question

var a = new String ("Hello");
var b = new String ("Hello");
if (a === b) {
alert ("a");
}
else {
alert ("b");
}

Answer 1

HonFu exactly!
a= "hello"
b= "hello"
Here there's just one "hello" in the string pool and both a and b are referencing to that one instead of having two distinct "hello" for a and b which is the case when you create string using string constructor.

Answer 2

You're creating two distinct instances of String class. Although both contains same value but still the two are different instances and hence a==b is false.

Answer 3

HonFu lol yeah and that's why it's the easiest language.. No such confusion 😅

Answer 4

M. Watney, but usually you can compare two equal strings, getting true, right?

How does this work? Is JS storing only one string of the same value like Python unless you specifically say otherwise by instantiation?

Answer 5

At least as long as you stick to the builtins with their clear immutable-mutable behavior.

write a class Str that holds a str for you and things may go differently. ;)

Answer 6

Thanks to all!! I'm a newbie in programming but now it's clear!!

Answer 7

Hm, funny, Python pools them even if you instantiate.

Good to know, thanks!

Answer 8

Does Java have a special "===" meaning? I'm not familiar with Java enough to decide if that might be the bug or if it is a legit thing.

Answer 9

https://code.sololearn.com/Wd5YjEiaFX4h/?ref=app

Answer 10

If we tweak the code a little -
var a = new String ("Hello");
var b = a;
if (a === b) {
alert("a");
}
else {
alert("b");
}
//Now the answer will be - a
//This is because now both the variables
//are referencing the same object unlike
//the original code