JavaScript return statement unexpected

Question

function returnSomething(){
    return 
    5;
}

This return undefined.

function returnSomething(){
    return 5;
}

This returns 5.

When I add new line after return, undefined is returned. I am using chrome. Is it the way V8 works?

Answer 1

This is the way JS works. Returns MUST begin the return block in the same line:

return {};

will return undefined, you should return: return {};

or

return { };

or

const isValid = false;
return isValid
    ? 5
    : 3;

By the way this is not v8, this is how JS has always worked

Answer 2

The number 5 is in new line. return statement ends in the single line even if you don't give the semi colon.
So your code is similar to :

function returnSomething(){
    return; // returns undefined.
    5;
}