Keyword search in string

Question

I need to perform a keyword search in a string. Similar to the below: If the Keyword is cancel, then the match should be true if the string is "Cancel the flight" and the match should be false if the string is "Cancelling the flight".

Also the keyword can be two words as well. For example: Booking code.

I tried the string methods like contains, equals etc. But they do not work.

Answer 1

Some people, when confronted with a problem, think "I know, I'll use regular expressions." Now they have two problems.

They really are the right tool for the job here though.

static Boolean keywordSearch(String input, String keywordPhrase)
{
    return Pattern.compile('(?i)\\b' + keywordPhrase + '\\b').matcher(input).find();
}

String corpus = 'The quick brown fox jumps over the lazy dog';
system.assert(keywordSearch(corpus, 'lazy dog'));
system.assert(keywordSearch(corpus, 'QUICK'));
system.assert(!keywordSearch(corpus, 'jump'));

The \b character indicates a word boundary. Wrap your phrase in that and see if it's in the input. The (?i) argument makes the whole thing case-insensitive.

Answer 2

well since you are concerned of the only the exact word match. I would suggest to split the search string into words such as String[] words = query.split(' ');

Then you can loop though all the words such as

integer ok=0;
for(integer i =0 ;i< words.size(); i++)
 if( words[i]=='Cancel')
  ok=1;

if(ok==1)
return query;
else 
return false;

You can adapt this example into a function. Note: I haven't tried out the code above so there might be some syntax errors, but this should give you a good starting point.

Answer 3

You can achieve this by using set as well.

String str = 'Cancel the flight';
set<String> set1 = new Set<String>();
set1.addAll(new List<String>(str.split(' ')));
system.debug('==='+set1.contains('Cancel'));

but here the string is case sensitive so if you search cancel in the above string it will return false.

Answer 4

So you have 2 strings in Apex like:

String s1 = 'Cancel the flight';
String s2 = 'Cancelling the flight';
String keyword = 'cancel';

And you need to determine if s1 and s2 contains keyword? What about Case sensitivity? keyword has a lower case c while s1 and s2 have capitol.

This will give you what you want. Remove the toLowerCase() call if you want case sensitive match.

new Set<String>(s1.toLowerCase().split(' ')).contains(keyword.toLowerCase());
new Set<String>(s2.toLowerCase().split(' ')).contains(keyword.toLowerCase());