使用 do while 循环连接

Question

我正在尝试读取用户输入，然后将这些词与 space 连接起来。我无法弄清楚循环中的逻辑。我还希望用户在输入完单词后能够告诉我的程序。这是我目前所拥有的……并不多。

Scanner in = new Scanner(System.in);

  String userWords = "";
  int number = 0;

  System.out.println("Enter words to build a sentence");
  userWords = in.nextLine();

  int i = 1;
  do {
      System.out.println(userWords);
      i++;
  } while (!(userWords.equals(null))); {
      System.out.println(userWords + " ");
  }

Answer 1

试试：

  Scanner in = new Scanner(System.in);
  String userWords = "";
  String currentWord = "";
  // now we print a prompt for user
  System.out.println("Enter words to build a sentence");  
  // here is the reading loop
  do {
      // now we read next line from user
      currentWord = in.nextLine();
      // now we add the user input to the userWords with " "
      userWords += currentWord +" ";
      // we end the loop when the currentWord will be empty
  } while (!(currentWord.trim().isEmpty())); 
  // now we print all the words
  System.out.println(userWords);

Answer 2

Scanner in = new Scanner(System.in);

  String enteredWord = "";
  StringBuilder builder = new sb();
  System.out.println("Enter words to build a sentence");
  enteredWord = in.nextLine();
  do {

      sb.append(enteredWord);
      sb.append(" ");
      enteredWord = in.nextLine();

  } while (!(enteredWord.equals("exit"))); 
//you may want to use a special case like %% instead because exit can be in a sentence{
          System.out.println(sb.toString());

这应该在大多数情况下都有效，我现在没有任何地方可以对其进行测试。每次循环都会添加后面带有 space 的单词，并要求输入一个新单词。您也可以使用 userwords += in.nextline() + " "; 但在循环中我总是会使用 stringbuilder 来提高效率。

使用 do while 循环连接

Concatenation using a do while loop

java

string

string-concatenation

do-while

sentinel