JavaScript

Question

what is the output of this code?
alert(-"1"+1+"2");

// answer is 02

Does anyone know how it came to be 2?

Answer 1

Hello!!

[-"1"]+1+"2" : the interpreter converted "1" to 1 because it was preceeded by -, so it was -1.

Now it is
[-1+1]+"2": you know -1+1 is 0;

[0+"2"]: this is sum between an integer and a string , 0 was converted to "0"(because i think alert() need strings ) ,so we have now "0"+"2" which is a simple concatenation , the result was "02".

The end!!

Answer 2

This is the problem with languages wchich does not have fixed type of a variable. Then you cannot remember it how it works respectively should work.