JAVA学习（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;
        System.out.println(a+b); //30
        System.out.println(a-b); //-10
        System.out.println(a*b); //200
        System.out.println(a/b); //0
        System.out.println((double)a/b); //0.5

    }
}

package operator;

public class Demo02 {
    public static void main(String[] args) {
        long a = 122892973929289L;
        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 operator;

public class Demo03 {
    public static void main(String[] args) {
        //关系运算符的返回结果：true false
        int a = 10;
        int b = 20;
        int c = 21;
        System.out.println(a>b);//false
        System.out.println(a<b);//true
        System.out.println(a==b);//false
        System.out.println(a!=b);//true
        System.out.println(c%a);//1 取余 模运算
    }
}

package operator;

public class Demo04 {
    public static void main(String[] args) {
        //++自增  --自减  一元运算符
        int a = 3;
        int b = a++;//执行完这段代码后，先赋值，再自增
        //a=a+1
        System.out.println(a);//4
        //a=a+1
        int c = ++a; //执行完这段代码前，先自增，再赋值
        System.out.println(a);//5
        System.out.println(b);//3
        System.out.println(c);//5
        //幂运算 2*2*2=8  很多运算，我们会使用一些工具类操作
        double pow = Math.pow(3,2);
        System.out.println(pow);
    }
}