Java运算符

package operator;

public class Demo01 {
    public static void main(String[] args) {
        // 二元运算符
        // ctrl+d 复制当前行到下一行
        int a = 10;
        int b = 20;
        int c = 10;
        int d = 10;

        System.out.println(a + b);
        System.out.println(a - b);
        System.out.println(a * b);
        System.out.println(a / (double) b);

    }
}

package operator;

public class Demo02 {
    public static void main(String[] args) {
        long a = 123123123123123L;
        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((double) c + d);  // c+d是Int类型
    }


}

package operator;

public class Demo03 {
    public static void main(String[] args) {
        // 关系运算符返回的结果： 正确 错误 布尔值
        int a = 10;
        int b = 20;
        int c = 21;

        System.out.println(c % a); // c / a  21/10=2余1，%就是取到余数，模运算，在Java里换了个名字
        System.out.println(a > b);
        System.out.println(a < b);
        System.out.println(a == b);
        System.out.println(a != b);
    }
}