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]•
public class laoyu { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[]={10,20,30,40,50}; for (int i = 0; i < a.length; i++) { System.out.println(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]•
public class laoyu { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub char a[]={'n','e','u','s','o','f','t'}; char []y=new char[a.length]; System.arraycopy(a, 0, y, 0, a.length); for (char i : y){ System.out.print(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)
import java.util.Arrays; public class laoyu { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[]={1,6,2,3,9,4,5,7,8}; Arrays.sort(a); for (int i : a) { System.out.print(i); } System.out.println(); for (int i = 0; i < a.length-1; i++) { for (int j = 0; j < a.length-1-i; j++) { if(a[j]>a[j+1]){ int b=a[j]; a[j]=a[j+1]; a[j+1]=b; } } } for (int i : a) { System.out.print(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)
public class AAAAA { /** * @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[i].length; j++) { a[i][j]=i+j; } } 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]•
import java.util.Arrays; public class AAAAA { /** * @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 b=1; for (int i = 0; i < a.length; i++) { if(a[i]>max){ max=a[i]; } } for (int i = 0; i < a.length; i++) { if(a[i]==max) b=i; } System.out.println("最大数"+max+"下标"+b); } }
作业
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) [选作题]•
import java.util.Scanner; public class Zuoye { /** * @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 = 0; i < a.length; i++) { a[i]=input.nextInt(); } int temp; for (int i = 0; i < a.length/2; i++) { temp=a[i]; a[i]=a[a.length-i-1]; a[a.length-i-1]=temp; } 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) [选作题]课后作业•
import java.util.Scanner; public class Zuoye { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int []a= {1,1,23,2,4,8,8}; 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)
import java.util.Scanner; public class Zuoye { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[]={ -10,2,3,246,-100,0,5}; int max=a[0]; int min=a[0]; int sum=0; double ave=sum/7; for (int i = 0; i < a.length; i++) { if(a[i]>max){ max=a[i]; } if(a[i]<min){ min=a[i]; } sum+=a[i]; ave=sum/7.0; } System.out.println("最大值为="+max+"最小值为="+min+"平均值="+ave); } }
9、使用数组存放裴波那契数列的前20项 ,并输出
int[] a = new int[20]; a[0] = 1; a[1] = 1; for (int i = 2; i < a.length; i++) { a[i] = a[i - 2] + a[i - 1]; } System.out.println("数列的前20项是"); for (int i = 0; i < a.length; i++) { System.out.print(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
import java.util.Random; import java.util.Scanner; public class Zuoye { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Random random = new Random(10); int b[] = new int[10]; for (int i = 0; i < b.length; i++) { b[i] = random.nextInt(200); System.out.print(" "+b[i]); } System.out.println(); for (int i = 0; i < b.length - 1; i++) { for (int j = 0; j < b.length - 1 - i; j++) { if (b[j] > b[j + 1]) { int temp = b[j]; b[j] = b[j + 1]; b[j + 1] = temp; } } } System.out.println(); for (int i = 0; i < b.length; i++) { System.out.print(" " + b[i]); } } }