Lösungsvorschläge

public int 01MyModulo(int a, int b)
    {
        int remainder=0;
        // dein Code
        remainder = a - a/b*b;
        // Rückgabe
        return remainder;
    }

oder

public int MyModulo(int a, int b)
    {
        return a - a/b*b;
    }

public void Switch(int a, int b) 
    {
        System.out.println("Eingabe - a="+ a + " b="+b);
 
        int c;
        c=a;
        a=b;
        b=c;
 
        System.out.println("Ausgabe - a="+ a + " b="+b);
     }

public void Switch(int a, int b) 
    {
        System.out.println("Eingabe - a="+ a + " b="+b);
 
        b = a + b;
        a = b - a;
        b = b - a;
 
        System.out.println("Ausgabe - a="+ a + " b="+b);
     }