package com.xuweiwei;

/**
 * 运算符
 */
public class Operator {
    public static void main(String[] args) {
        //定义变量
        int x = 3;
        int y = 4;

        System.out.println(x+y);
        System.out.println(x-y);
        System.out.println(x*y);
        System.out.println(x/y);//整数相除只能得到整数
        System.out.println(x%y);//取余

        /**
         * 如果我想要整数相除不是得到整数，只需要把操作数其中一个操作数变为浮点数即可
         */
        System.out.println(x*1.0/y);

    }
}

package com.xuweiwei;

/**
 * ++、--运算符的应用
 */
public class Operator2 {
    public static void main(String[] args) {
        //定义两个变量
        int x = 3;
        int y = 4;

        System.out.println("x:"+x);
        System.out.println("y:"+y);

        //单独使用
        x++; //相当于x=x+1;
        y++;
        System.out.println("x:"+x);
        System.out.println("y:"+y);



        x =3;
        y=4;
        //参与运算
        int a = x++; //++在后面，先赋值，再自增
        int b = ++y; //++在前面，先自增，再赋值
        System.out.println("x:"+x);
        System.out.println("y:"+y);
        System.out.println("a:"+a);
        System.out.println("b:"+b);


    }
}

package com.xuweiwei;

/**
 * 赋值运算符
 */
public class Operator3 {
    public static void main(String[] args) {
        int x = 10;

        System.out.println("x:" + x);

        int y = 10;
        y += 20; //相当于y = y + 20;
        System.out.println("y:" + y);
    }
}

package com.xuweiwei;

/**
 * 关系运算符
 */
public class Operator4 {
    public static void main(String[] args) {
        int a = 3;
        int b = 4;

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

    }
}

package com.xuweiwei;

/**
 * 逻辑运算符
 * 特点：
 * 逻辑运算符一般用于连接boollean类型的表达式或值
 */
public class Operator5 {
    public static void main(String[] args) {
        int a = 3;
        int b = 4;
        int c = 5;

        //&：一假全假
        System.out.println((a > b) & (a > c)); //false & false = false
        System.out.println((a > b) & (a < c)); //false & true = false
        System.out.println((a < b) & (a > c)); //true & false = false
        System.out.println((a < b) & (a < c)); //true & true = true

        //|：一真全真
        System.out.println((a > b) | (a > c)); //false & false = false
        System.out.println((a > b) | (a < c)); //false & true = true
        System.out.println((a < b) | (a > c)); //true & false = true
        System.out.println((a < b) | (a < c)); //true & true = true

        //^：相同为false，不同为true
        System.out.println((a > b) ^ (a > c)); //false ^ false = false
        System.out.println((a > b) ^ (a < c)); //false ^ true = true
        System.out.println((a < b) ^ (a > c)); //true ^ false = true
        System.out.println((a < b) ^ (a < c)); //true ^ true = false
    }
}

package com.xuweiwei;

/**
 * 位运算符：
 */
public class Operator6 {
    public static void main(String[] args) {
        int a = 3;
        int b = 4;

        System.out.println(a & b);
        System.out.println(a | b);
        System.out.println(a ^ b);
        System.out.println(~a);
    }
}

package com.xuweiwei;

/**
 * ^
 * 一个数据对另一个数据异或两次，该数本身不变
 */
public class Operator7 {
    public static void main(String[] args) {
        int a = 3;
        int b = 4;

        System.out.println(a ^ b ^ b);
        System.out.println(a ^ b ^ a);
    }
}

package com.xuweiwei;

/**
 * << :左边最高为丢弃，右边补0
 * >> :最高位为0的时候，左边补齐0；最高位为1的时候，左边补齐1
 * >>> :无论最高位是0还是1，左边补齐0
 */
public class Operator8 {
    public static void main(String[] args) {
        System.out.println(3 << 2);
        System.out.println(24 >> 2);
        System.out.println(-24 >>> 2);
    }
}

package com.xuweiwei;

/**
 * 使用三目运算符求两个数的最大值
 */
public class Operator9 {
    public static void main(String[] args) {
        int a = 10;
        int b = 20;

        System.out.println(a >= b ? a : b);
    }
}

package com.xuweiwei;

/**
 * 顺序结构
 */
public class orderDemo {
    public static void main(String[] args) {
        System.out.println("程序开始了");

        System.out.println("I love java");

        System.out.println("程序结束了");
    }

}

if(关系表达式){
  语句体;  
}

package com.xuweiwei;

public class IfDemo1 {
    public static void main(String[] args) {
        int x = 10;
        if (x >= 10) {
            System.out.println("x>=10");
        }
        System.out.println("程序执行结束了");
    }
}