第八次作业
上机
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 bbb; public class test1 { /** * @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]?
package array; import java.util.Arrays; public class Array2 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub String[] a = { "neusofteducation" }; String[] b = new String[a.length]; System.arraycopy(a, 0, b, 0, a.length); System.out.println(Arrays.toString(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)
packageaaa; publicclass Test2 { /** * @paramargs */ publicstaticvoid 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 - 1; i++) { for (int j = 0; j <a.length - 1 - i; j++) { if (a[j] > a[j + 1]) { int temp = a[j]; a[j] = a[j + 1]; a[j + 1] = temp; } } } for (int i : a) { System.out.println(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 Test5; public class h1 { /** * @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.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)
package Test5; public class h1 { /** * @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 number=0; for (int i = 1; i < a.length; i++) { if (a[i]>max) { max=a[i]; } number++; } System.out.println("最大值为:"+max); System.out.println("下标为:"+number); } }
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)
package text1; import java.util.Scanner; public class HelloWorid{ public static void main(String[] args) { Scanner input=new Scanner(System.in); System.out.println("请输入数组中元素个数:" ); int x=input.nextInt(); int a[]=new int[x]; System.out.println("请输入数组元素:" ); for (int i = 0; i < x; i++) { a[i]=input.nextInt(); } System.out.println("逆序存放:" ); for (int j = x-1; j > 0; j--) { System.out.print(a[j]); } System.out.println(a[0]); } }
7. 将一个数组中的重复元素保留一个其他的清零
package arrays; public class Test07 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int[] a = { 1, 1, 2, 3, 2, 0, 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 = 0; i < a.length; i++) { System.out.println(a[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)
public class asdfsd { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[]={ -10,2,3,246,-100,0,5}; int i=0; int sum=0; for(;i<6;i++){ if(a[i]>a[i+1]){ System.out.println("最大值"+a[i]); } if(a[i+1]<a[i]) { System.out.println("最小值"+a[i+1]); } sum=sum+a[i]; } System.out.println("平均值"+sum/7); } }
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 homework; public class HM9 { /** * @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
package Fourth; import java.util.Arrays; import java.util.Random; public class Ften { /** * @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("输出10个100以内的随机数"); for (int i = 0; i < a.length; i++) { a[i] = x.nextInt(101); } for (int i = 0; i < a.length; i++) { System.out.println(a[i]); } System.out.println("经排序后 "); Arrays.sort(a); for (int i = 0; i < a.length; i++) { System.out.println(a[i]); } } }