java第六周随堂

1.编写一个简单程序，要求数组长度为5，静态赋值10，20，30，40，50，在控制台输出该数组的值。

package dome6_sixthweek_Thursday;

public class a {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int[] arr = { 10, 20, 30, 40, 50 };
		for (int i = 0; i < arr.length; i++) {
			System.out.print(arr[i] + " ");
		}

	}

}

　　

2.编写一个简单程序，要求数组长度为5，动态赋值10，20，30，40，50，在控制台输出该数组的值。

package dome6_sixthweek_Thursday;

import java.util.Scanner;

public class b {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		int[] num = new int[5];
		Scanner input = new Scanner(System.in);
		int i;
		for (i = 0; i < num.length; i++) {
			System.out.print("请输入第" + (i + 1) + "个数:");
			num[i] = input.nextInt();
		}
		for (i = 0; i < num.length; i++) {
			System.out.print(num[i] + " ");
		}

	}

}

　　

3.编写一个简单程序，定义整型数组，里面的元素是{23,45,22,33,56}，求数组元素的和、平均值

package dome6_sixthweek_Thursday;

public class c {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int sum = 0;
		int[] arr = { 23, 45, 22, 33, 56 };
		for (int i = 0; i < 5; i++) {
			sum += arr[i];

		}
		System.out.println("和为" + sum);
		System.out.println("平均值为" + sum / 5);

	}

}

　　

4.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 dome6_sixthweek_Thursday;

public class d {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int[] arr = { 18, 25, 7, 36, 13, 2, 89, 63 };
		int max = arr[0];
		int i = 0;
		int x = 0;
		for (i = 0; i < arr.length; i++) {
			if (arr[i] > max) {
				max = arr[i];
				x = i;
			}
		}
		System.out.println("最大值为" + max + "下标为" + x);

	}

}

　　

5． 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 dome6_sixthweek_Thursday;

public class e {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int arr[] = { 10, 20, 30, 40, 50 };
		for (int i = 0; i < arr.length; i++) {
			System.out.print(arr[i] + " ");
		}
		System.out.println();
		for (int i = 0; i < arr.length / 2; i++) {

			int temp = arr[i];
			arr[i] = arr[arr.length - 1 - i];
			arr[arr.length - 1 - i] = temp;
		}
		for (int i = 0; i < arr.length; i++) {
			System.out.print(arr[i] + " ");
		}

	}

}

　　

6、有一个已经排好序的数组。现输入一个数，要求按原来的规律将它插入数组中。（附加题）

package dome6_sixthweek_Thursday;

import java.util.Scanner;

public class f {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int[] num = new int[5];
		Scanner input = new Scanner(System.in);
		for (int i = 0; i < num.length - 1; i++) {
			System.out.print("请输入第" + (i + 1) + "个数:");
			num[i] = input.nextInt();
		}
		for (int i = 0; i < num.length - 1; i++) {
			for (int j = 0; j < num.length - 1 - i; j++) {
				if (num[j] > num[j + 1]) {
					int temp = num[j];
					num[j] = num[j + 1];
					num[j + 1] = temp;
				}
			}
		}
		for (int i = 0; i < num.length; i++) {
			System.out.print(num[i] + " ");
		}
		System.out.println(" ");
		System.out.print("请输入要插入的数:");
		num[0] = input.nextInt();
		for (int i = 0; i < num.length - 1; i++) {
			for (int j = 0; j < num.length - 1 - i; j++) {
				if (num[j] > num[j + 1]) {
					int temp = num[j];
					num[j] = num[j + 1];
					num[j + 1] = temp;
				}
			}
		}
		for (int i = 0; i < num.length; i++) {
			System.out.print(num[i] + " ");
		}

	}

}