字符串得到错误的值

Question

我正在尝试构建一个类似于 11 11 的字符串，但我遇到了问题，我正在为 start 获取以下字符串 98 11 而不是 11 11.

我该如何解决？

感谢任何帮助。

Character number = newName.charAt(2); //here number is 1
Character numberBefore = newName.charAt(1); //here numberBefore is 1

try (PrintWriter writer = new PrintWriter(path+File.separator+newName);
    Scanner scanner = new Scanner(file)) {
  boolean shouldPrint = false;
  while (scanner.hasNextLine()) {
  String line = scanner.nextLine();

  if(numberBefore >0 ){
    String start= number+number+" "+number+number; //here start is `98 11`
  }

Answer 1

是的，这是由于+的结合性。

这个：

String start= number+number+" "+number+number;

有效：

String start = (((number + number) + " ") + number) + number;

所以你得到 number + number（正在对 int 执行数字提升）和 then 字符串连接。

听起来你想要：

String numberString = String.valueOf(number);
String start = numberString + numberString + " " + numberString + numberString;

或者：

String start = String.format("%0c%0c %0c%0c", number);

Answer 2

是的，这是因为 +

的结合性

你也可以试试下面的代码

String c1 =Character.toString(number);
String s =c1+c1+" "+c1+c1;

Answer 3

        String newName = "111";
    Character number = newName.charAt(2); // here number is 1
    Character numberBefore = newName.charAt(1); // here numberBefore is 1

    if (Character.getNumericValue(numberBefore) > 0) {  // checking against numeric rather than ascii
        System.out.println("ASCII value of char " + (int) number); // ASCII code for '1' = 49
        String start = String.valueOf(number) + String.valueOf(number) + " " + number + number; // here start is `98 11`
        System.out.println(start);
    }
}

字符串得到错误的值

The string is getting the wrong value

java

string

stringbuilder