java学习9.23

public class Ts
{
public static void main(String[] args)
  {
int a = 13; int b = 2;
         //a += b;  //a = a + b;
//a -= b;  //a = a - b;
//a *= b;  //a = a * b;
//a /= b;  //a = a / b;
a %= b;  //a = a % b;
System.out.println(a);
System.out.println(b);
  }

}

public class Boolean
{
public static void main(String[] args)
  {
 char a = 'a';// 'a' = 97;
 boolean b = 5 <= a;
 double c = 9.987;
 b = c <= a;
 b = 2<3 & 3>4 ;
 b = 2<3 | 3>4 ;
 b = 2<3 ^ 3>4 ; // 异或 的判断条件是 两边相同是假 两边不同是真
 b = 2<3 && 3>4 ; //  & 与 && 的区别是 &判断是执行所有判断语句之后执行  &&判断是从前往后执行 只要有假即结束 判断结果
 System.out.println(b);
  }
}

public class Sanmu
{
public static void main(String[] args)
{
 int a = 3>7 ? 1+2 : 2+3 ; //先判断问号之前 如果是真 执行冒号前内容 如果是假 执行冒           //号后内容
 System.out.println(a);
 int b = 5;   //冒号前后 数据类型必须保持一致
 String s = b<6 ? "今天继续上班" : "今天可以休息" ;
 System.out.println(s);
 //位运算 & | 与 或
 //  &        101
 //           110   按位与 得 100  是4
 System.out.println(5 & 6);  
 //位移运算  <<  >>
 //     <<2       1010
 //             101000     按二进制向左 移动 两位
}
}

public class lianxi
{
public static void main(String[] args)
{
String Zijia ="自加运算符用法展示";
String Zifuchuan = "字符串相加展示";
int f=1;
int d=2;
int t=f+d;
System.out.println("f和d的和是"+t);
f = f++;
System.out.println(Zijia +"  结果是  " + f);
f = ++f;
System.out.println(Zijia +"  结果是   " + f);
System.out.println(Zifuchuan + "已经展示过了");
String Fuzhiyunsuanfu ="赋值运算符展示";
f += d;
System.out.println(Fuzhiyunsuanfu +"   " + f);
f *= d;
System.out.println(Fuzhiyunsuanfu +"   " + f);
System.out.println(Fuzhiyunsuanfu + "已经展示过了");
boolean n = f < d & f <= d;
System.out.println(n);
int a=3; int b=4;
System.out.println("使用条件运算符");
String s= (a<6)?"a小于b":"a大于b";
System.out.println(s);
System.out.println("使用if条件语句显示");
if(a<b)
{ System.out.println("a小于b");}
else
{ System.out.println("a大于b");}
}
}

public class If
{
public static void main(String[] args)
{
/*
int a = 3,b = 5;
int max;
if (a<b)
{
max = b;
System.out.println("a和b的最大值是"+max);
}
else
{
max = a;
System.out.println("a和b的最大值是"+max);
}
System.out.println("______end_______");
判断一个数是否是水仙花数？
                水仙花数：
       （1）它是一个三位整数
       （2）个位数字的立方+十位数字的立方+百位数字的立方=它本身
       如：153=1的立方+5的立方+3的立方


*/
int x = 153,a,b,c;
a = x / 100;
b = (x - a * 100) / 10;
c = x - a * 100 - b * 10;
System.out.println(a);
System.out.println(b);
System.out.println(c);
if (a*a*a+b*b*b+c*c*c == x)
{
System.out.println(x + "是水仙花数");
}
else 
{
System.out.println(x + "不是水仙花红数");
}
a = 89;
if(a>=90)
{System.out.println("成绩是" + a + "等级为A");}
else if(a>=80)
{System.out.println("成绩是" + a + "等级为B");}
else if(a>=70)
{System.out.println("成绩是" + a + "等级为C");}
else if(a>=60)
{System.out.println("成绩是" + a + "等级为D");}
else
{System.out.println("成绩是" + a + "不及格");}




int m = 123;
if(m/1000 != 0)
{System.out.println("m是四位数");}
else if (m/100 !=0)
{System.out.println("m是三位数");}
else if (m/10 !=0)
{System.out.println("m是两位数");}
else
{System.out.println("m是个位数");}
}
}

public class zuoye{
public static void main(String[] args){
//交换数
int a,b,c; a = 2; b = 3;
c = a; a = b; b = c;
System.out.println("a = " + a);
System.out.println("b = " + b);
//工资
int time =170; int money;
if(time <= 160){
money = time * 30;
System.out.println("工资是" + money);
} else {
money = (time - 160) * 45 + 160 * 45;
System.out.println("工资是" + money);
}
//回文数
int num =12345; int a1,a2,a3,a4,a5;
a1 = num / 10000;
a2 = (num - a1 * 10000) / 1000;  // a2 = num / 1000 % 10;
a3 = (num - a1 * 10000 - a2 * 1000) / 100;
a4 = (num - a1 * 10000 - a2 * 1000 - a3 * 100) / 10; // a4 = num / 10 % 10;
a5 = num - a1 * 10000 - a2 * 1000 - a3 * 100 - a4 * 10;  //a5 = num % 10;
if (a1 == a5 && a2 == a4){
System.out.println("num是回文数");
}else{
System.out.println("num不是回文数");
}
//判断成绩
a = 89;
if(100>=a && a>=90)
{System.out.println("成绩是" + a + "等级为优");}
else if(90>a && a>=80)
{System.out.println("成绩是" + a + "等级为良");}
else if(80>a && a>=60)
{System.out.println("成绩是" + a + "等级为中");}
else 
{System.out.println("成绩是" + a + "等级为差");}
}
}

public class jiujiu 
{
public static void main(String[] args)
{
int a = 0;
for(int b = 1;b < 10;b++)
{
for(int c =1;c < b + 1; c++)
{
a = c * b;
System.out.print("  " + c + "*" + b + "=" + a);
}
System.out.println();
}
}
}