How does return (string.splice(" ").join"") in a function differ from string.splice(" ").join("") and then return string?

Question

I try to understand a conceptual difference between:

var x = '8aaaaa dddd r     '

function noSpace(x){
  return (x.split(" ").join(""));
}
noSpace(x) //Results in "8aaaaaddddr"

AND

var x = '8aaaaa dddd r     '

function noSpace(x){
  x.split(" ").join("");
  return x;
}

noSpace(x) //Results in "8aaaaa dddd r     "

Why does the second version don't work as the first one?

Primitives are immutable. If a variable name holds a primitive value, that variable name will always continue to reference that same primitive value unless explicitly reassigned. Only with objects can you see side-effects to some variable without explicit reassignment — CertainPerformance, Sep 06 '19 at 08:15
`'splice' !== 'split'`. btw, no need to wrap the value for `return`. — Nina Scholz, Sep 06 '19 at 08:15
`split` and `join` return the split or joined string and do not update the value of `x` directly — phuzi, Sep 06 '19 at 08:16
As @CertainPerformance said, 2nd case does practically nothing. You have to do smth like `x = x.split(" ").join("");` — Pavel Třupek, Sep 06 '19 at 08:17
thx @PavelTřupek that helped me most to understand the concept — Stephan - the curious, Sep 06 '19 at 08:19
@NinaScholz yeah, because splice is for arrays, right? Or did you want me to tell anything else? — Stephan - the curious, Sep 06 '19 at 08:21
@user2132380, i refer to the subject and the code and a possible mixup. `slice` and `split` are methods of `String` as well as `slice` and `splice` are methods of `Array`. both features `slice` with same parameters. — Nina Scholz, Sep 06 '19 at 08:24
It's impossible to change a primitive in-place, as referenced in a number of places in the link. There's probably a better dupe link around, this sort of question isn't uncommon — CertainPerformance, Sep 06 '19 at 08:26

0 Answers0