所以我的程序应该访问一个文本文档，然后执行所有当前有效的爵士乐。我想不通的唯一问题是如何洗牌数组的内容而不让它们最终相互重叠。互联网和随机和 for 循环的多次尝试都没有结果。这是我的代码:
import java.io.*;
import java.util.*;
public class lab_6 {
public static void main(String[] args)throws FileNotFoundException {
Scanner input = new Scanner(System.in); //reads from keyboard
System.out.println("What is the name of your file. ");
String name = input.nextLine();
Scanner reader = new Scanner(new File(name));// Open text file
System.out.println("how many names are in your array");
int num = input.nextInt();
String[] names = new String[num];
for (int index = 0; index< names.length; index++)
{
names[index] = reader.nextLine();// Gets a line while there is one
}
System.out.println("\nOriginal List");
printList(names);
System.out.println("\nShuffled List");
shuffle(names);
printList(names);
System.out.println("\nSorted List");
Arrays.sort(names); // this is a built in method
printList(names);
System.out.println("What name are you looking for");
Scanner input1 = new Scanner(System.in); //reads from keyboard
String find = input1.nextLine();
int index = search(names,find);
if(index == -1)
System.out.println("The name was not there");
else
System.out.println(find+" was found at position "+index);
System.out.println("The average length of all the names is "+averageLength(names));
}
public static void printList(String[] array) // print the list of names numbered
{
for (int i=0; i<array.length; i++)
{
System.out.println((i+1)+") "+ array[i]);
}
}
public static void shuffle (String[] array) // mix-up the array
{
}
public static int search(String[] array, String find)
{
for(int i=0; i<array.length; i++) {
if (array[i].equals(find) ) return i;
}
return -1;
}
public static double averageLength(String[] array) //return the average length of the names
{
int sum=0;
for (int i=0; i<array.length; i++)
{
int l= array[i].length();
sum +=l;
}
int average = sum/(array.length);
return average;
}
}
最佳答案
String[] names = ...;
Collections.shuffle(Arrays.asList(names));
// done
请注意，Arrays.asList() 返回一个可修改(但固定长度)的列表，由数组支持，而不是数组的副本。因此数组将被打乱。
关于java - 如何打乱数组的内容，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22312827/