Question

有没有办法复制像这样的字符串并将其放入数组？

String s =“Hello”; - ＆GT; String [] s = {“Hello”，“Hello”};

数组必须复制s中的内容。

Answer 1

您可以创建一个类似

的方法

public class MyGraph{

 //filled with strings from file
 String[] points;
 java.io.File file;
 java.util.Scanner input;
 //length of points array
 int numPoints;

 public MyGraph(String file){

   this.file = new java.io.File(file);
   this.input = new java.util.Scanner(file);

   this.numPoints = this.input.nextInt();
   this.points = new String[this.numPoints];

   fillGraphArray();


  }

  //after getting the number of vertices we populate the array with   every
 //line after those points untill the end
 private void fillGraphArray(){

   //used once after reading nextInt()
   this.input.nextLine();

   int count = 0;
   while(this.input.hasNext() == true){

     points[count] = input.nextLine();

     count++;
   }

   input.close();
}

//test method to be delted later
public String[] getPoints(){

   return this.points;
}

//may need a method to close the file
}

Answer 2

你可以这样做：

Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.

Wed Mar 07 22:48:57 UTC 2018
There was an unexpected error (type=Internal Server Error, status=500).
Unable to acquire JDBC Connection; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC Connection

或：

String[] resultSet = IntStream.rangeClosed(1, n)
                              .mapToObj(i -> s)
                              .toArray(String[]::new);

其中String[] resultSet = Stream.generate(() -> s) .limit(n) .toArray(String[]::new);是您要生成字符串n的次数。

示例：

会打印：

int n = 2;
String s = "Hello";
String[] resultSet = IntStream.rangeClosed(1, n)
                              .mapToObj(i -> s)
                              .toArray(String[]::new);

System.out.println(Arrays.toString(resultSet));

复制一个字符串（相同的值）并将其转换为数组

2 个答案: