How to give return type to jawa program?

Answer 1

return type of a function in Java:

boolean isPrime(x){
for(int i=1;i<x;i++){
if(x % i == 0){
return false;
}
}
return true;
}

return types are:
boolean (true/false)
int (Integer; .., -1, 0, 1, 2, ...)
double (.., -1.0, -1.0...1, 0.0, ... 1,01)
...

Answer 2

they are writen istead of void.
void means nothing is returned