Java中的字符串匹配和替换

Question

I have a String like this:

String a = "Barbara Liskov (born Barbara Jane Huberman on November 7, 1939"
+" in California) is a computer scientist.[2] She is currently the Ford"
+" Professor of Engineering in the MIT School of Engineering's electrical"
+" engineering and computer science department and an institute professor"
+" at the Massachusetts Institute of Technology.[3]";

I would like to replace all of these elements: [1] , [2] , [3] , etcetera, with a blank space.

I tried with:

if (a.matches("([){1}\\d(]){1}")) {
    a = a.replace("");
}

but it does not work!

Answer 1

Your Pattern is all wrong.

Try this example:

String input = 
      "Barbara Liskov (born Barbara Jane Huberman on November 7, 1939 in California) "
    + "is a computer scientist.[2] She is currently the Ford Professor of Engineering "
    + "in the MIT School of Engineering's electrical engineering and computer "
    + "science department and an institute professor at the Massachusetts Institute " 
    + "of Technology.[3]";
//                                   | escaped opening square bracket
//                                   |  | any digit
//                                   |  |   | escaped closing square bracket
//                                   |  |   |      | replace with one space
System.out.println(input.replaceAll("\\[\\d+\\]", " "));

Output (newlines added for clarity)

Barbara Liskov (born Barbara Jane Huberman on November 7, 
1939 in California) is a computer scientist. 
She is currently the Ford Professor of Engineering in the MIT 
School of Engineering's electrical engineering and computer science 
department and an institute professor at the Massachusetts Institute of Technology.

Answer 2

Very simple:

   a = a.replaceAll("\\[\\d+\\]","");

The changes:

1. Use replaceAll instead of replace

2. Escape the [] - they are regex special chars. the partnerships are not escaping them.

3. No need of {1} on your regex [{1} == [ - both are specifying that the character should be one time

4. The + added to d+ is for more than one digits numbers such as [12]

Answer 3

About your pattern ([){1}\\\\d(]){1} :

• {1} is always useless since always implicit
• [ and ] needs to be escaped with a backslash (which must itself be escaped with another backslash since in a string literal)
• \\\\d has no explicit cardinality, so [12] for example won't match since there are two digits

So, better try: \\\\[\\\\d+\\\\]

Answer 4

Use the String replaceAll(String regex, String replacement) .

All you got to do is a=a.replaceAll("\\\\[\\\\d+\\\\]", " ") .

You can read Javadoc for more information .

Answer 5

Use this:

String a = "Barbara Liskov (born Barbara Jane Huberman on November 7, 1939 in California) is a computer scientist.[2] She is currently the Ford Professor of Engineering in the MIT School of Engineering's electrical engineering and computer science department and an institute professor at the Massachusetts Institute of Technology.[3]";

        for(int i =1 ; i<= 3; i++){
               a= a.replace("["+i+"]","");
        }
        System.out.println(a);

This will work.