JavaSE 遍历数组和冒泡排序

遍历数组快捷键：

累加：

package array;

public class TraversingArray {
    
    
    public static void main(String[] args) {
    
    
        int sum = 0;
        // 遍历数组元素
        int[] arr = {
    
    12,22,34,45,67};
        for (int i = 0; i < arr.length; i++) {
    
    
            System.out.println(arr[i]);
            sum += arr[i];
        }

        System.out.println(sum);
    }
}

求最大值：

package array;

public class MaxValue {
    
    
    public static void main(String[] args) {
    
    
        // 求最值
        int[] values= {
    
    19,22,89,100,67,45,101,34};
        int tempMax = values[0];
        for (int i = 1; i < values.length; i++) {
    
    
            if (values[i] > tempMax) {
    
    
                tempMax = values[i];
            }
        }

        System.out.println("max value is " + tempMax);
    }
}

猜数字：

package array;

import java.util.Random;
import java.util.Scanner;

public class GuessNumber {
    
    
    public static void main(String[] args) {
    
    
        // 5个1-20随机数 让用户猜 猜中提示数据第一次在数组中出现的索引值 为猜中则继续

        int[] data = new int[5];
        Random r = new Random();
        for (int i = 0; i < data.length; i++) {
    
    
            data[i] = r.nextInt(20) + 1;
        }

        Scanner sc = new Scanner(System.in);
        OUT:
        while(true) {
    
    
            System.out.println("input a integer between 1-20 and guess:");
            int guessData = sc.nextInt();

            for (int i = 0; i < data.length; i++) {
    
    
                if (data[i] == guessData) {
    
    
                    System.out.println("Bingo! The number is " + data[i] + " number index is " + i);
                    break OUT;
                }
            }
            System.out.println("Guess Again!");
        }

        for (int i = 0; i < data.length; i++) {
    
    
            System.out.print(data[i] + "\t");
        }
    }
}

推出OUT循环：

随机排名：

package array;

import java.util.Random;
import java.util.Scanner;

public class RandomSort {
    
    
    public static void main(String[] args) {
    
    
        int[] staffNumber = new int[5];

        Scanner sc = new Scanner(System.in);
        for (int i = 0; i < staffNumber.length; i++) {
    
    
            System.out.println("input staff[" + (i+1) +"]'s number");
            staffNumber[i] = sc.nextInt();
        }

        for (int i = 0; i < staffNumber.length; i++) {
    
    
            System.out.print(staffNumber[i] + "\t");
        }

        // exchange values
        Random r = new Random();
        for (int i = 0; i < staffNumber.length; i++) {
    
    
            int randIndex = r.nextInt(staffNumber.length);

            int temp = staffNumber[i];
            staffNumber[i] = staffNumber[randIndex];
            staffNumber[randIndex] = temp;
        }
        System.out.println("\r");

        for (int i = 0; i < staffNumber.length; i++) {
    
    
            System.out.print(staffNumber[i] + "\t");
        }
    }
}

数组排序：

package array;

public class BubbleSort {
    
    
    public static void main(String[] args) {
    
    
        int[] arr = {
    
    10,33,44,76,23,78,102,65,45,36,98,1,20,52,66,21,28,99,7};

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

        // 定义循环控制比较轮数
        for (int i = 1; i <= arr.length - 1; i++) {
    
    
            // 定义一个循环控制每轮比较的次数
            for (int j = 0; j < arr.length - i; j++) {
    
    
                if (arr[j] > arr[j+1]) {
    
    
                    int temp = arr[j];
                    arr[j] = arr[j+1];
                    arr[j+1] = temp;
                }
            }
        }
        System.out.println("\r");

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