help with slice

Question

so I can do like this:
function zero(x) {
return (""+x).slice(2)
}
console.log(zero(123456789));

but why I can't do like this?
function zero(x) {
return (x).slice(2)
}
console.log(zero(123456789));

Answer 1

slice() function is a member function of String class.

You can only use that with string, not with integers.

But in the above mentioned program you have to use slice() with an int variable, i.e., x
So, if you want to use that with any int, then you have to change int into string.
So for converting into string ""+x is used.

Answer 2

Gabriel Junior Precisely, you are correct! 😋

Answer 3

oh so that's why
function zero(x) {
return String(x).slice(2)
}

console.log(zero(123456789));
also works