Java第八次作业
1、编写一个简单程序,要求数组长度为5,分别赋值10,20,30,40,50,在控制台输出该数组的值。(知识点:数组定义和创建、一维数组初始化)[必做题]?
package homework8; import java.util.Scanner; public class Text1 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int []a=new int[5]; Scanner input=new Scanner(System.in); for (int i = 0; i < a.length; i++) { a[i]=input.nextInt(); } for (int i = 0; i < a.length; i++) { System.out.print(a[i]+" "); } } }
2、将一个字符数组的值(neusofteducation)拷贝到另一个字符数组中。(知识点:数组复制) [必做题]?
package homework8; public class Text2 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub char[]a={'o','k'}; char[]b=new char[2]; System.arraycopy(a,0,b,0,2); for (int i = 0; i < b.length; i++) { System.out.print(b[i]); } } }
3、给定一个有9个整数(1,6,2,3,9,4,5,7,8)的数组,先排序,然后输出排序后的数组的值。(知识点:Arrays.sort排序、冒泡排序)
package homework8; public class Text3 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int[] point={1,6,2,3,9,4,5,7,8}; java.util.Arrays.sort(point); for (int i = 0; i < point.length; i++) { System.out.print(point[i]+" "); } } }
4、 输出一个double型二维数组(长度分别为5、4,值自己设定)的值。(知识点:数组定义和创建、多维数组初始化、数组遍历)
package homework8; public class Text4 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub double a[][]=new double[5][4]; for (int i = 0; i < a.length; i++) { for (int j = 0; j < a[j].length; j++) { a[i][j]=i; } } System.out.println("矩阵是"); for (int i = 0; i < a.length; i++) { for (int j = 0; j < a[i].length; j++) { System.out.print(a[i][j]+" "); } System.out.println(); } } }
5、 在一个有8个整数(18,25,7,36,13,2,89,63)的数组中找出其中最大的数及其下标。(知识点:数组遍历、数组元素访问) [必做题]?
package homework8; public class Text5 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int []a={18,25,7,36,13,2,89,63}; int max=a[0]; int maxidx=0; for (int i = 0; i < a.length; i++) { if(a[i]>max){ max=a[i]; maxidx=i; } } System.out.println("最大值"+max+"下标为"+maxidx); } }
6、将一个数组中的元素逆序存放(知识点:数组遍历、数组元素访问)
package homework8; import java.util.Scanner; public class Text6 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input=new Scanner(System.in); int a[]=new int[5]; for (int i = a.length; i > 0; i--) { a[i-1]=input.nextInt(); } System.out.println("逆序输出"); for (int i = 0; i < a.length; i++) { System.out.print(a[i]+" "); } } }
7. 将一个数组中的重复元素保留一个其他的清零。(知识点:数组遍历、数组元素访问)
package homework8; public class Text7 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int []a= {1,3,3,5,5}; for (int i = 0; i < a.length; i++) { for (int j = 0; j < a.length; j++) { if(a[i]==a[j]&&i!=j) { a[j]=0; } } } for (int i : a) { System.out.println(i); } } }
8、给定一维数组{ -10,2,3,246,-100,0,5},计算出数组中的平均值、最大值、最小值。(知识点:数组遍历、数组元素访问)
package homework8; public class Text8 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[]={-10,2,3,246,-100,0,5}; double pingJun=0; double sum=0; for (int i = 0; i < a.length; i++) { sum+=a[i]; } pingJun=sum/a.length; int zuiDa=a[0]; int zuiXiao=a[0]; for (int i = 0; i < a.length; i++) { if(a[i]>zuiDa){ zuiDa=a[i]; } if(a[i]<zuiXiao){ zuiXiao=a[i]; } } System.out.println("平均值"+pingJun+"\n最大值"+zuiDa+"\n最小值"+zuiXiao); } }
9、使用数组存放裴波那契数列的前20项 ,并输出 1 1 2 3 5 8 13 21
package homework8; public class Text9 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[]=new int[20]; a[0]=1; a[1]=1; for (int i = 2; i < a.length; i++) { a[i]=a[i-1]+a[i-2]; } for (int i = 0; i < a.length; i++) { System.out.println(a[i]); } } }
10、生成一个长度为10的随机整数数组(每个数都是0-100之间),输出,排序后,再输出
package homework8; import java.util.Arrays; import java.util.Random; public class Text91 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[]=new int[10]; Random b=new Random(); for (int i = 0; i < a.length; i++) { a[i]=b.nextInt(101); } for (int i = 0; i < a.length; i++) { System.out.print(a[i]+" "); } System.out.println("\n排序后"); Arrays.sort(a); for (int i = 0; i < a.length; i++) { System.out.print(a[i]+" "); } } }