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 zy; public class z8 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int []a={10,20,30,40,50}; System.out.println("输出数组:"); 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 zy; public class z8 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub char []l={'a', 'b', 'c', 'd', 'e'}; char []x=new char[l.length]; System.arraycopy(l, 0, x, 0, l.length); for (int i = 0; i < x.length; i++) { System.out.println(x[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。
package zy; public class z8 { /** * @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 = 0; j < a.length - 1; j++) { if (a[j] > a[j + 1]) { int temp = a[j]; a[j] = a[j + 1]; a[j + 1] = temp; } } } for (int i = 0; i < a.length; i++) { System.out.println(a[i]); } } }
package zy; import java.util.Arrays; public class z8 { /** * @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。
package zy; public class z8 { /** * @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。
package zy; public class z8 { /** * @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 max = a[0]; int low = 0; for (int i = 0; i < a.length; i++) { if (a[i] > max) { max = a[i]; low = i; } } System.out.println("下标:" + low); System.out.println("最大值:" + max); } }
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 zy; public class z8 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int[] a = new int[] { 5,7,8,9,12,36 }; int temp; for (int i = 0; i < a.length/2; i++) { temp=a[i]; a[i]=a[a.length-1-i]; a[a.length-1-i]=temp; } for (int i = 0; i < a.length; 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 zy; public class z8 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int[] a = { 1, 3, 7, 6, 1, 2, 9, 3 }; 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。
package zy; public class z8 { /** * @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]; int b = 0; for (int i = 0; i < a.length; i++) { sum += a[i]; if (a[i] > max) max = a[i]; if (a[i] < min) min = a[i]; } b = sum / 7; System.out.println("最大值:" + max + "最小值:" + min + "平均值:" + b); } }
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 zy; public class z8 { /** * @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-2]+a[i-1]; } for(int i=0;i<8;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 zy; import java.util.Arrays; import java.util.Random; public class z8 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int l[] = new int[10]; Random x = new Random(); for (int i = 0; i < l.length; i++) { l[i] = x.nextInt(101); } for (int i = 0; i < l.length; i++) { System.out.println(l[i]); } System.out.println("排序后: "); Arrays.sort(l); for (int i = 0; i < l.length; i++) { System.out.println(l[i]); } } }