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Thread: Searching a string for a single character - how to?

  1. #1
    Junior Member
    Join Date
    May 2012
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    Cool Searching a string for a single character - how to?

    I can't use the 'at' symbol because these forums restrict it, so I'll replace the at symbol with &.

    I'm trying to search a string for the "&" character but it seems as though my regex is not working..

    Here is what I have:

    CharSequence cs = ".*&.*";
    CharSequence cs2 = ".*&a-b.c.d";
    boolean csRet = users[i].contains(cs); //Currently everything returns false.
    	if (!csRet) {
    		users[i] += "&a-b.c.d";
    boolean csCraRet = users[i].contains(cs2);
    	if (cs2Ret) {
                   //Do stuff

  2. #2
    Administrator copeg's Avatar
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    Oct 2009
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    Default Re: Searching a string for a single character - how to?

    See the API for the contains method you are using (I am guessing 'users' is an array of String objects) - does it use regular expressions?

  3. #3
    Forum VIP
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    Jul 2010
    Thanked 329 Times in 305 Posts

    Default Re: Searching a string for a single character - how to?

    Contains searches for exact Strings, not regexes.
    String does have a "matches" method which accepts regexes, but it checks the ENTIRE String. There are two ways around this:
    1. Add a wildcard to the front and back of your regex and use String.matches(String regex) method (you need to add a wildcard to account for additional text before and after the regex).
    2. Use the Pattern and Matcher classes instead:
    Pattern p = Pattern.compile(regex_pattern); // Creates a new Pattern object with the specified regex
    Matcher m = p.matcher(inputString); // Creates a new Matcher object from the Pattern, with the String you are wanting to search
    boolean exists = m.find(); // Returns true if the regex pattern is found in the String

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