运算符与自增自减

运算符与自增自减

package cperator;

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 = 30;
       int d = 40;

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


   }
}

package cperator;

public class Demo02 {
    public static void main(String[] args) {
        long a = 123123123123L;
        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
    }
}

package cperator;

public class Demo03 {
    public static void main(String[] args) {
        //关系运算返回结果 ：正确，错误    布尔值
        // if

        int a = 10;
        int b = 20;
        int c = 21;

        //取余模运算
        System.out.println(c%a);//c/a    21/10 = 2...1

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

package cperator;

public class Demo04 {
    public static void main(String[] args) {
        //++  --   自增，自减   一元运算符
        int a = 3;

        int b = a++;//执行完这行代码后，先给b赋值，再自增
        //a++   a=a+1
        System.out.println(a);
        //a++   a=a+1
        int c = ++a;//执行完这行代码前，先自增，再给b赋值

        System.out.println(a);
        System.out.println(b);
        System.out.println(c);

        //幂运算 2^3  2*2*2 = 8
        double pow = Math.pow(3, 2);
        System.out.println(pow);
    }
}