作业2:习题

1、 判断以下程序的输出结果:

 1 public class Test1 {
 2     public static void main(String[] args) {
 3            int x = 10;
 4            int a = x + x++;
 5            System.out.println("a="+a);
 6            System.out.println("x="+x);
 7            int b = x + ++x;
 8            System.out.println("b="+b);
 9            System.out.println("x="+x);
10            int c = x + x--;
11            System.out.println("c="+c);
12            System.out.println("x="+x);
13            int d = x + --x;
14            System.out.println("d="+d);
15            System.out.println("x="+x);
16     }
17 }

运行结果:

 

 2、

 1 public class Test2 {
 2     public static void main(String[] args) {
 3           int a = 15;
 4           int b = 2;
 5           double c = 2;
 6           System.out.println(a+"/"+b+"="+(a/b));
 7           System.out.println(a+"%"+b+"="+(a%b));
 8           System.out.println(a+"/"+c+"="+(a/c));
 9           System.out.println(a+"%"+c+"="+(a%c));
10     }
11 }

运行结果:

 

 3、

 1 public class Test3 {
 2     public static void main(String[] args) {
 3           boolean x,y,z;
 4           int a = 15;
 5           int b = 2;
 6           x = a>b;
 7           y = a<b;
 8           z = a!=b;
 9           System.out.println("x="+x);
10           System.out.println("y="+y);
11           System.out.println("z="+z);
12     }
13 }

运行结果:

 

 4、  判断以下程序的输出结果:

 1 public class Test4 {
 2     public static void main(String[] args) {
 3            int x;
 4            double y;
 5            x = (int)22.5+(int)34.7;
 6            y = (double)x;
 7            System.out.println("x="+x);
 8            System.out.println("y="+y);
 9     }
10 }

输出结果:

 

 5、判断以下程序的输出结果:

 1 public class Test5 {
 2     public static void main(String[] args) {
 3           int i = 5;
 4           int j = 5;
 5           int m = 5;
 6           int n = 5;
 7           i++;      //这行代码执行结束之后,i是6
 8           j = j+1;  //这行代码执行结束之后,j是6
 9           m--;      //这行代码执行结束之后,m是4
10           n = n-1;  //这行代码执行结束之后,n是4
11           System.out.println(i); 
12           System.out.println(i++);6(虽然输出结果是6,但是这行代码执行结束之后,i是7)
13           System.out.println(++i);
14           System.out.println(i--);
15           System.out.println(--i);
16           System.out.println();
17           System.out.println(j);
18           System.out.println(j++);
19           System.out.println(j--);
20           System.out.println(--j);
21           System.out.println();
22           System.out.println(m);
23           System.out.println(n);
24     }
25 }

运行结果:

 

 6、判断以下程序的输出结果

 1 public class Test6 {
 2     public static void main(String[] args) {
 3            int i = 0;
 4            int j = 0;
 5            System.out.println(i);
 6            System.out.println(j);
 7            i++;
 8            ++j;
 9            System.out.println(i);
10            System.out.println(j);
11            System.out.println("---------------");
12            System.out.println(i++);
13            System.out.println(++j);
14            System.out.println("---------------");
15            System.out.println(i);
16            System.out.println(j);
17     }
18 }

运行结果:

 

posted @ 2021-04-11 20:33  lraj  阅读(70)  评论(0编辑  收藏  举报