I have a simple question about the "return" statement. Example is in the code. I always think the isPrime(n) is always "true". Because the "return true;" is at the end of the method, it should over-write previous returns. Any one can help? The codes are running perfect, producing the right results.
private boolean isPrime(int n) {
for(int i = 2; i < n; i++) {
if (n % i == 0) return false;
}
return true;
}
'return' exits the function returning whatever value you return. The last return is never reached so it won't return the default value.
No, once you return from a method, you're done. If you want to convince yourself, insert print statements, or run it through a debugger.
If if (n % i == 0) is true it executes return false; and will exit the method. return true; will only be reached if return false; can't be executed.
No, a second return does not override an earlier one, it is never even reached. Control leaves the method immediately upon return.
(The only way for that not to happen would be to have a second return inside of a finally block. That would indeed change the return value. But is is highly discouraged)
Functions don't fully execute and then return, they can exit at any point during the execution with a return statement.
So if a number is found to n % i == 0 then the subroutine will return false and exit.
If the function completed the for loop and never resolved the if statement it returns true and exits.
