第八周上机作业
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)
package com.fj.sjlx; public class Sjlx1 { /** * @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)
package com.fj.sjlx; public class Sjlx2 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub String []a={"neusoft"}; String []b=new String[a.length]; System.arraycopy(a, 0, b, 0, a.length); for (String string : b) { System.out.println(string); } } }
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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 com.fj.sjlx; public class Sjlx3 { /** * @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-1; i++) { for (int j = 0; j < a.length-1-i; j++) { if(a[j]<a[j+1]){ int kz=a[j]; a[j]=a[j+1]; a[j+1]=kz; } } } 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)
package com.fj.sjlx; public class Sjlx4 { /** * @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]=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)
package com.fj.sjlx; public class Sjlx5 { /** * @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=0,index=0; for (int i = 0; i < a.length; i++) { if(a[i]>max){ max=a[i]; index=i; } } System.out.println("最大值是:"+max+"下标是:"+index); } }
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 com.fj.hahaha; public class Home { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[] = { 18, 25, 7, 36, 13, 2, 89, 63 }; for (int i = a.length-1; i >= 0; 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 com.fj.hahaha; public class Home { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[] = { 10, 25, 28, 25, 26, 25, 27 }; 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.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 com.fj.hahaha; public class Home { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int a[] = { -10, 2, 3, 246, -100, 0, 5 }; int pjz = 0, max = 0, min = 0; int sum = 0; for (int i = 0; i < a.length; i++) { sum += a[i]; pjz = sum / 7; if (a[i] > max) { max = a[i]; } if (a[i] < min) { min = a[i]; } } System.out.println("平均值为:" + pjz); System.out.println("最大值为:" + max); System.out.println("最小值为:" + 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 com.fj.hahaha; public class Home { /** * @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.print(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 com.fj.hahaha; import java.util.Arrays; import java.util.Random; public class Home { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Random r = new Random(); int x[] = new int[10]; for (int i = 0; i < x.length; i++) { x[i] = r.nextInt(101); } for (int i = 0; i < x.length; i++) { System.out.print(x[i] + " "); } Arrays.sort(x); System.out.println(); for (int i = 0; i < x.length; i++) { System.out.print(x[i] + " "); } } }