狂神说--基础语法--基础运算符

 

 

 

算数运算符：

　　+-*/

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
        //以下为局部变量
        int a = 10;
        int b = 20;
        int c = 25;
        int d = 25;

        System.out.println(a+b);
        System.out.println(a-b);
        System.out.println(a*b);
        System.out.println(a/(double)b);//强制转换1个即可
    }
}

package operator;

public class Demo02 {
    public static void main(String[] args) {
        long a = 123456789L;
        int b = 123;
        short c = 10;
        byte d = 8;
        //有Long类型 则返回Long类型 否则都返回Int类型
        System.out.println(a+b+c+d);//Long
        System.out.println(b+c+d);//Int
        System.out.println(c+d);//Int

    }
}

　　关系运算符

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;

        //大于、小于、等于、不等于
        System.out.println(a>b);
        System.out.println(a<b);
        System.out.println(a==b);
        System.out.println(a!=b);

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