Java运行程序写结果(答案)

1 Java练习题 四、运行程序写结果 1. 当在命令提示符后输入”java SumTest 4 5”之后，下列程序的输出结果为：

4+5=9 public class SumTest { public static void main(String[] args) { int a, b, sum; a=Integer.parseInt(args[0]); b=Integer.parseInt(args[1]); sum=a+b; System.out.println(a + "+" + b + "=" + sum); } }

2. 当在命令提示符后输入”java PrintStar 8”之后，下列程序的输出结果为： ********

public class PrintStar { public static void main(String[] args) { int n = Integer.parseInt(args[0]); int i; for( i=1; i<=n; i++) System.out.print("*"); System.out.println(); } }

3. 当在命令提示符后输入”java CalculateTest 5.5”之后，下列程序的输出结果为：

10.0

public class CalculateTest{ public static void main(String args[]){ float x,y; x = Float.parseFloat(args[0]); if(x<1) y = x; else if(1<=x&&x<10) 2

y = 2*x-1; else y = 3*x-11; System.out.println(y); } }

4. 当在命令提示符后输入”java Factorial3 3”之后，下列程序的输出结果为： 结果是：6

public class Factorial3 { public static void main(String[] args) { int num = Integer.parseInt(args[0]); int result = 1; if(num<1) System.out.println("应输入大于1的整数！"); else{ int i; for( i=1; i<=num; i++) result = result*i; System.out.println("结果是："+result); } } }

5. 下列程序的输出结果为： null public class X{ public static void main(String [] args) { String names[]=new String[5]; for(int x=0;xnames[x]=args[x]; System.out.println(names[2]); } }

6. 下列程序的输出结果为: 9.5 10.0 8 public class Test{ public static void main(String[] args) { System.out.print ( 3.5+1/2+56%10+" " ); System.out.print ( 3.5+1.0/2+56%10+" " ); 3

int a = 4%3*7+1; System.out.println( a ); } }

a[0] = 1 a[1] = 2 a[2] = 3 7. 下列程序的输出结果为： a[3] = 4 a[4] =5 public class A1 { public static void main(String args[]) { int a[]=new int[5]; a[0]=1; a[1]=2; a[2]=3; a[3]=4; a[4]=5; System.out.print("a["+0+"] = "+a[0]+" "); System.out.print("a["+1+"] = "+a[1]+" "); System.out.println("a["+2+"] = "+a[2]+" "); System.out.print("a["+3+"] = "+a[3]+" "); System.out.print("a["+4+"] = "+a[4]); } }

8. 下列程序的输出结果为： a[4]=4, a[3]=3, a[2]=2, a[1]=1,a[0]=0, public class array1D_1 { public static void main(String args[]) { int i; int a[ ]; a = new int[5]; for(i=0;i<5;i++) a[i]=i; for(i=a.length-1;i>=0;i--) System.out.print(“a[“ +i + ”]=” + a[i] + ”,\t”); } }

9. 运行结果是： Hi ! Like public class Test1 { String str = new String("Hi !"); char[] ch = { 'L', 'i', 'k', 'e' }; public static void main(String args[]) { Test1 ex = new Test1(); System.out.print(ex.str + " "); System.out.print(ex.ch); 4

} }

10. 运行结果是： 4 6 8 10 12 14 16 18 20 public class Test3 { public static void main(String[] args) { int i; for (i = 3; i <= 20; i ++) { if ((i % 2) == 0) System.out.print(i + " "); } } }

11. 运行结果是： i=21,sum=108 public class Test4 { public static void main(String[] args) { int i,sum=0; for (i = 3; i <= 20; i ++) if ((i % 2) == 0) sum=sum+i; System.out.print("i="+i+",sum="+sum);

} }

12. 运行结果是： 2500 public class Test5 { public static void main(String[] args) { int i,sum=0; for (i = 1; i <= 100; i ++) { if ((i % 2) == 1) sum=sum+i; } System.out.println(sum); } 5

} 13. 运行结果是： 0 1 2 3 4 5 6 7 8 9 class Test6 { public static void main(String[] args) { int i; for(i=0;i<10;i++){ System.out.print(i+" "); if (i%2!=0) continue; System.out.println(" "); } } }

14、运行结果是： 3 5 7 11 13 17 19 23 29 public class Test14 { public static void main(String[] args) { int n = 1, m, j, i; for (i = 3; i <= 30; i += 2) { m = (int) Math.sqrt((double) i); for (j = 2; j <= m; j++) if ((i % j) == 0) break; if (j >= m + 1) { System.out.print(i + " "); if (n % 5 == 0) System.out.print("\n"); n++; } 6

} } }

15. 下列程序的输出结果为： 1 4 9 16 25 36 49 64 81 100 total is 385 public class Test1 { public static void main(String args[]) { int y, x=1, total=0; while(x<=10) { y=x*x; System.out.print(y+" "); total+=y; ++x; } System.out.print("total is "+total); } }

16. 下列程序的输出结果为： copy every letter public class WhileExample{ public static void main(String[] args){ String copyFromMe="Copy every letter until you encounter 'u'."; StringBuffer copyToMe=new StringBuffer(); //创建一个空的串变量 int i=0; char c=copyFromMe.charAt(i); while(c!='u') { copyToMe.append(c); c=copyFromMe.charAt(++i); } System.out.println(copyToMe); } }

17. 下列程序的输出结果为： Found 1076 at i=1, j=2 public class BreakExample{ public static void main(String[] args){ int[ ][ ] array={{32,87,3},{589,12,1076},{2000,8,622}}; int search = 1076, i=0, j=0; boolean foundIt = false; for (i=0; i<3; i++) { for (j=0; j<3; j++){ if (array[i][j] == search) { foundIt = true; break; } //跳出内层循环