关于#数组#的问题，如何解决？Java

数组不能在方法中实现保存

```java
package week15_activity3;

import java.util.Scanner;

public class menu_driven {
    public static void main(String[] args) {
        while(true){
            System.out.println("1:Accept elements of an array from the user\n" +
                    "2:Display elements of the array \n" +
                    "3:Search an element given by the user within that array \n" +
                    "4:Sort the array using the bubble sort method.\n"+
                    "Please choose you need：");
            Scanner s = new Scanner(System.in);
            int a = s.nextInt();
            switch (a){
                case 1:
                    int array[] = accept();
                    continue;
                case 2:
                    display(array);
                    continue;
                case 3:
                    search(array);
                    continue;
                case 4:
                    sort1(array);
                    continue;
                case 5:
                    break;
            }
        }
    }
    public static int[] accept() {
        Scanner s1 = new Scanner(System.in);
        System.out.println("请输入数组（空格隔开）：");
        String str = s1.next();
        String[] arr = str.split(" ");
        int[] b = new int[arr.length];
        for (int j = 0; j < b.length; j++) {
            b[j] = Integer.parseInt(arr[j]);
        }
        return b;
    }
    public static void display(int[] a){
        System.out.println("该数组内容：");
        for (int i = 0; i < a.length; i++) {
            System.out.println(a[i]+" ");
        }
    }
    public static void search(int[] a){
        Scanner s2 = new Scanner(System.in);
        System.out.println("请输入要查找的数：");
        int index = s2.nextInt();
        int flag = 0;
        for (int i = 0; i < a.length; i++) {
            if(index == a[i]){
                System.out.println("已找到，该元素在数组中的下标为："+i+"\n");
                flag = 1;
                break;
            }
        }
        if(flag == 0){
            System.out.println("未找到该元素\n");
        }
    }
    public static void sort1(int[] a){
        for (int i = 0; i < a.length; i++) {
            for (int j = 1;jif(a[j-1]>a[j]){
                    int t = a[j-1];
                    a[j-1] = a[j];
                    a[j] = t;
                }
            }
        }
        System.out.println("已排序，排序结果为：");
        for (int i = 0; i < a.length; i++) {
            System.out.println(a[i]);
        }
    }
}

```

超出了变量生命周期

将array定义在循环外部，第二个问题，accept接受多个数字要使用nextLine()而不是next
程序修改如下：

import java.util.Scanner;

public class menu_driven  {
    public static void main(String[] args) {
        int array[] = null;
        while(true){
            System.out.println("1:Accept elements of an array from the user\n" +
                    "2:Display elements of the array \n" +
                    "3:Search an element given by the user within that array \n" +
                    "4:Sort the array using the bubble sort method.\n"+
                    "Please choose you need：");
            Scanner s = new Scanner(System.in);
            int a = s.nextInt();
            switch (a){
                case 1:
                     array = accept();
                    continue;
                case 2:
                    display(array);
                    continue;
                case 3:
                    search(array);
                    continue;
                case 4:
                    sort1(array);
                    continue;
                case 5:
                    break;
            }
        }
    }
    public static int[] accept() {
        Scanner s1 = new Scanner(System.in);
        System.out.println("请输入数组（空格隔开）：");
        String str = s1.nextLine();
        String[] arr = str.split(" ");
        int[] b = new int[arr.length];
        for (int j = 0; j < b.length; j++) {
            b[j] = Integer.parseInt(arr[j]);
        }
        return b;
    }
    public static void display(int[] a){
        System.out.println("该数组内容：");
        for (int i = 0; i < a.length; i++) {
            System.out.println(a[i]+" ");
        }
    }
    public static void search(int[] a){
        Scanner s2 = new Scanner(System.in);
        System.out.println("请输入要查找的数：");
        int index = s2.nextInt();
        int flag = 0;
        for (int i = 0; i < a.length; i++) {
            if(index == a[i]){
                System.out.println("已找到，该元素在数组中的下标为："+i+"\n");
                flag = 1;
                break;
            }
        }
        if(flag == 0){
            System.out.println("未找到该元素\n");
        }
    }
    public static void sort1(int[] a){
        for (int i = 0; i < a.length; i++) {
            for (int j = 1;j<a.length-i;j++){
                if(a[j-1]>a[j]){
                    int t = a[j-1];
                    a[j-1] = a[j];
                    a[j] = t;
                }
            }
        }
        System.out.println("已排序，排序结果为：");
        for (int i = 0; i < a.length; i++) {
            System.out.println(a[i]);
        }
    }
}

运行结果：