public class Demo {
    public static void main(String[] args) {
        long a = 1231231231L;
        int b = 123;
        short c = 10;
        byte d = 8;
        System.out.println (a+b+c+d);//long
        System.out.println(b+c+d);//int
        System.out.println(c+d);//int
        //如果有一个数为long他的结果就是long 如果有一个数是double或float结果就是double或float都存在就是double
        System.out.println("===========================");
        int aa = 20;
        int bb = 10;
        int cc = 21;
        System.out.println(cc%bb); //  cc/bb = 21/10 = 2余1  取余数1

        System.out.println(a>b);
        System.out.println(a<b);
        System.out.println(a==b);
        System.out.println(a!=b);
    }