第八次JAVA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 haha; public class feige { /** * @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 haha; public class test2 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub char []c={'a','b','c','d','e'}; char []b=new char[c.length]; for (int i = 0; i < c.length; i++) { b[i]=c[i]; } for (int i = 0; i < 5; i++) { System.out.println(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 haha; import java.util.Arrays; public class work { /** * @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.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 haha; import java.util.Scanner; public class tese4 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method adtub 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; } } 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]?
public class test5 { /** * @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],min=a[0]; int maxidx=0,minidx=0; for (int i = 0; i < a.length; i++) { if(a[i]>max){ max=a[i]; maxidx=i; } if(a[i]<min){ min=a[i]; minidx=i; } } { System.out.println("最大值是"+max+"最大值下标是"+maxidx); System.out.println("最小值是"+min+"最小值下标是"+minidx); } } }
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 work; import java.util.Scanner; public class test1 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); System.out.println("请输入数组中的元素个数"); int l= input.nextInt(); int[] a = new int[s]; for (int i = 0; i < l; i++) { System.out.println("请输入第" + (i + 1) + "个数"); a[i] = input.nextInt(); } System.out.println("倒序输出为"); for (int i = l - 1; i >= 0; i--) { System.out.println(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 work; importjava.util.Scanner; publicclass test2 {/***@paramargs*/publicstaticvoidmain(String[] args) { //TODO Auto-generated method stubint[] a = { 1, 2, 3, 4, 4, 5, 6, 7}; for(inti : a) { System.out.print(i+ " "); } System.out.println(); for(inti = 0; i < a.length; i++) { for(intj = 0; j < a.length; j++) { if(a[i] == a[j] && i !=j) a[j]= 0; } } System.out.println("将重复的元素清零后的数组:"); for(inti : a) { System.out.print(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 work; public class test3 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int[] a = { -10, 2, 3, 246, -100, 0, 5 }; int sum = 0; int max = a[0]; int min = a[0]; for (int i = 0; i < a.length; i++) { sum += a[i]; if (max < a[i]) max = a[i]; if (min > a[i]) min = a[i]; } System.out.println("平均数:" + sum / a.length); System.out.println("最大值:" + max); System.out.println("最小值:" + min); } }
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 work; public class test4 { /** * @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 work; import java.util.Random; public class test5 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int[] a = new int[10]; Random sj = new Random(); System.out.println("产生的随机数组为"); for (int i = 0; i < a.length; i++) { a[i] = sj.nextInt(100); System.out.print(a[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 m = a[j]; a[j] = a[j + 1]; a[j + 1] = m; } } } System.out.println("排序后的数组为"); for (int i : a) { System.out.print(i + " "); } } }