Strings contained in strings

[John Lockheart]

What's the best way to go about checking if a String being searched for is contained within another String (ignoring case).

ex) Cat is contained in Catastraphy

I searched the string class online but found no functions that might help me do this. Maybe just using indexOf() with a string parameter, because that way if I don't get back an index it's not there, and if I do it is there? I'm trying to keep a record of which strings contain other strings, like all the strings in a list that contain the word "Cat" for example. Thanks

[Jorge Pinho]

Hi John,

You have to use regular expressions...

look for...

String.matches()

and

Pattern Class, to understand Regular Expressions

[Ernest Friedman-Hill]

Using indexOf() this way is common and a fine thing to do; but it will only find exact matches, including letter case. A more general solution would be to use regular expressions -- String.matches() or its more general form java.util.regex.Pattern.matches(). Something like

// Keep "p", use for all your Strings to check if they contain "cat"
Pattern p = Pattern.compile(".*cat.*", Pattern.CASE_INSENSITIVE);

// For each string you want to match
Matcher m = p.matcher(theString);
boolean containsCatIgnoringCase = m.matches();

[Sean Connery]

You could also try doing:

    
String x = "Catastraphy"; 
 
int i = x.toLowerCase().indexOf("cat"); 

Then test the value of i to see if "cat" existed in the original string.

[Campbell Ritchie]

"Ubuntu Climber," please check the JavaRanch naming policy and adjust your displayed name accordingly.