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]
import java.util.Scanner; public class ss { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input=new Scanner(System.in); int []a={10,20,30,40,50}; for (int i = 0; i < a.length; i++) { System.out.print(a[i]); System.out.print(" "); } } }
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 cn.test; public class Work2 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub char[] a = { 'n', 'e', 'u', 's', 'o', 'f', 't', 'e', 'd', 'u', 'c', 'a', 't', 'i', 'o', 'n' }; char[] b = new char[a.length]; for (int i = 0; i < b.length; i++) { b[i] = a[i]; } System.out.println(b); } }
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.Scanner; public class ss { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int []a={1,6,2,3,9,4,5,7,8}; java.util.Arrays.sort(a); for (int i = 0; i < a.length; i++) { System.out.println(a[i]); } } }
import java.util.Scanner; public class ss { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int []a={1,6,2,3,9,4,5,7,8}; for (int i = 0; i < a.length; i++) { for (int j = i+1; j < a.length-1; j++) { if(a[j]>a[j+1]){ int c=a[j]; a[j]=a[j+1]; a[j+1]=c; } } } for (int i = 0; i < a.length; i++) { System.out.println(a[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)
import java.util.Scanner; public class ss { /** * @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; } } 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.print(" "); } 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.Random; import java.util.Scanner; public class ss { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int []a = new int[]{ 18, 25, 7, 36, 1, 2, 89, 63 }; int s = a[0]; int c = 0; for (int i = 0; i < a.length; i++) { if (a[i] > s) { s = a[i]; c = i; } } System.out.println("下标为" + c); System.out.println("最大值为" + s);
}
}
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]•
package cn.test; public class Work6 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int num[]={2021,4,23}; for (int i = 0; i < num.length/2; i++) { int temp; temp=num[i]; num[i]=num[num.length-1-i]; num[num.length-1-i]=temp; } for (int i = 0; i < num.length; i++) { System.out.println(num[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 ss { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[] = new int[] { 1,0,0,2,3,4,4}; 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 x: a) { System.out.print(x); System.out.print(" "); } } }
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
public class Work8 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[] = { -10, 2, 3, 246, -100, 0, 5 }; double average = 0; double sum = 0; for (int i = 0; i < a.length; i++) { sum += a[i]; } average = sum / a.length; int max = a[0]; int min = a[0]; for (int i = 1; i < a.length; i++) { if (a[i] > max) { max = a[i]; } if (a[i] < min) { min = a[i]; } } System.out.println("平均数是" + average + "\t" + "最大值是" + max + "\t" + "最小值是" + min); } }
9、使用数组存放裴波那契数列的前20项 ,并输出
public class Work9 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int x[] = new int[20]; x[0] = 1; x[1] = 1; for (int i = 2; i < x.length; i++) { x[i] = x[i - 1] + x[i - 2]; } for (int i = 0; i < 8; i++) { System.out.println(x[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; import java.util.Arrays; public class ss { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[]=new int[10]; Random x=new Random(); System.out.println("创建的100以内的随机数"); for (int i = 0; i < a.length; i++) { a[i]=x.nextInt(100); } for (int i = 0; i < a.length; i++) { System.out.print(a[i]+" "); } System.out.println(); System.out.println("排序后"); Arrays.sort(a); for (int i = 0; i < a.length; i++) { System.out.print(a[i]+" "); } } }