osman - 1 year ago 97
Java Question

# Can somebody please explain this code?

I do not understand the code.

Could someone explain me step by step (code by code)?

Note: The purpose of the method is to ask for and recieve user input;

followed by checking the number to see if it's a prime number.

``````package prime;
import java.util.Scanner;

public class primetime {
public static void main(String [] args){
Scanner input = new Scanner (System.in);
System.out.print("Enter a number: ");
int a = input.nextInt();
for ( int b = 2; b < a; b++){
int z = a%b;
if (z == 0){

}

}
if (a == 1){
System.out.println("(Not a) Prime number (1) (Not all mathematicians count 1 as a prime number)");
}
System.out.println("Prime number (" + a + ")" );
}
else{
System.out.println("Not a prime number (" + a + ")");
}

}
}
``````

A scanner (`new Scanner(System.in)`) is for taking inputs and transferring to Strings, ints, ... . Scanner a is one of them. Then it prints `"Enter a number: "`, And int `a` is the method of scanner called `nextInt()`. Then the client (the user) types a number. Then it creates a `boolean` called `primeNumber` and sets it to `true`. It creates a for loop that starts at `2`, and repeats untill it's `a`. Then it does:
integer z is the leftovers of how much b fits in a (that operation is called `Modulo` or `%`). If z = 0, its even, so the sum b/a would be a hole number. Then `primeNumber` is `false`. At the end it check what `primeNumber` is. It prints the text that you can see in your code. I'm sure you know what `if` is (and i hope you can read the language of 'keine' or 'PrimZahl').