java - 更改 catch block 内变量的值

Question

代码如下:

public static String removeDateFromString(String txt) {
    String dateRemovedString = new String();
    String[] str = txt.split("-");

    for(int i=0; i<str.length; i++) {

        SimpleDateFormat format = new SimpleDateFormat("dd MMM");
        try {
            format.parse(str[i]);
        } catch(ParseException e) {
            dateRemovedString.concat(str[i]);
        }
    }
    return dateRemovedString;
}

对于，

输入文本:板球比赛 - 7 月 1 日

输出文本:""(空字符串)

但我想要，输出:Cricket Match

我该怎么办？

Answer 1

字符串是 immutable :

Note: The String class is immutable, so that once it is created a String object cannot be changed. The String class has a number of methods, some of which will be discussed below, that appear to modify strings. Since strings are immutable, what these methods really do is create and return a new string that contains the result of the operation.

dateRemovedString = dateRemovedString.concat(str[i]);

---

StringBuilder 是可变的。 StringBuilder 用于构建 字符串。在这种情况下，请改用 StringBuilder。用法示例:

StringBuilder dateRemovedString = new StringBuilder();
dateRemovedString.append(str[i]);
return dateRemovedString.toString();