How can I provide an OR operator in regular expressions?
java, regex
Solution
Generally speaking about regexes, you definitely should begin your journey into Regex wonderland here: Regex tutorial
What you currently need is the `|` (pipe character)
To match the strings `one` OR `other`, use:
(one|other)
or if you don't want to store the matches, just simply
one|other
To be Java specific, this article is very good at explaining the subject
You will have to use your patterns this way:
//Pattern and Matcher
Pattern compiledPattern = Pattern.compile(myPatternString);
Matcher matcher = pattern.matcher(myStringToMatch);
boolean isNextMatch = matcher.find(); //find next match, it exists,
if(isNextMatch) {
String matchedString = myStrin.substring(matcher.start(),matcher.end());
}
Please note, there are much more possibilities regarding Matcher then what I displayed here...
//String functions
boolean didItMatch = myString.matches(myPatternString); //same as Pattern.matches();
String allReplacedString = myString.replaceAll(myPatternString, replacement)
String firstReplacedString = myString.replaceFirst(myPatternString, replacement)
String[] splitParts = myString.split(myPatternString, howManyPartsAtMost);
Also, I'd highly recommend using online regex checkers such as Regexplanet (Java) or regex101, they make your life a lot easier!
Problem
I want to match my string to one sequence or another, and it has to match at least one of them. For `and` I learned it can be done with: ``` (?=one)(?=other) ``` Is there something like this for OR? I am using Java, Matcher and Pattern classes.