英文:
Matching + character with Java Regex
问题
我正在编写一个程序来验证社会保障号码。我使用的是格式为YYMMDD-XXXX的10位数字，并且我需要验证日期是否正确。
如果一个人已经满100岁，那么“-”字符会被替换为“+”，我需要识别出这一点。
我正在使用equals()方法来实现这个目标，根据https://stackoverflow.com/questions/610333/how-to-replace-a-plus-character-using-javas-string-replaceall-method 的说法，我应该能够通过"\\+"来识别加号。
然而，以下方法仍然返回false：
public static boolean is100(String sweID) {
if ((sweID.substring(6,7)).equals("\\+")) {
return true;
} else {
return false;
}
}
我知道针对这个特定问题的明显解决方法：我可以简单地编写一个正则表达式来识别“-”字符，因为那不是一个特殊字符。然而，我很好奇为什么我不能使这个方法起作用。
最好的问候，
Felix
英文:
I am writing a program to verify social security ID:s. I am working with 10 digits in the format YYMMDD-XXXX, and I need to verify if the dates are correct.
If a person is turning 100 years old, the "-" character is replaced with "+", and I need to identify this.
I am using the equals() method to achieve this goal, and according to https://stackoverflow.com/questions/610333/how-to-replace-a-plus-character-using-javas-string-replaceall-method , I should be able to identify the plus sign using "\\+".
However, the following method still returns false:
public static boolean is100(String sweID) {
if ((sweID.substring(6,7)).equals("\\+")) {
return true;
} else {
return false;
}
}
I am aware of the obvious workaround for this particular: I could simply write a Regex that identifies the "-" character instead, since that is not a special character. However, I am curious to why I am not able to make this work.
Best regards
Felix
答案1
得分: 2
你正在将字符串中的第7个字符与字符串\+进行比较。这里没有正则表达式。你正在使用常规的String.equals方法，所以你可以直接传递字符串+。
或者这样写也可以：
sweID.charAt(6) == '+';
另外，代替这种写法：
if (condition)
return true;
else
return false;
你可以直接写成：
return condition;
英文:
You're comparing the 7th character in the string with the string \+. There are no regular expressions here. You're using the regular String.equals method so you can just pass it the string +.
Or this would work:
sweID.charAt(6) == '+'
Also, instead of
if (condition)
return true;
else
return false;
you can just do
return condition;
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