wordEnds : Solutions for Javabat : 21

Given a string and a non-empty word string, return a string made of each char just before and just after every appearance of the word in the string. Ignore cases where there is no char before or after the word, and a char may be included twice if it is between two words.

wordEnds("abcXY123XYijk", "XY") → "c13i"
wordEnds("XY123XY", "XY") → "13"
wordEnds("XY1XY", "XY") → "11"

Source

public String wordEnds(String str, String word) {
   if(str.indexOf(word)==-1 | str.equals(word)) return "";
    
       String ends="";
         for(int i=0  ; i<str.length() ; i++){
              i=str.indexOf(word, i);
              
              if(i==0) {                               // in the begining
                ends+=""+str.charAt(i+word.length());
                i=i+word.length()-1;
              }
              else if(i==str.length()-word.length()){ // in the end
                ends+=""+str.charAt(i-1);
                break;
              }
              else if(i==-1) break; // no more matches
              else{   // in the middle
                ends+=""+str.charAt(i-1)+str.charAt(i+word.length());
                i=i+word.length()-1;
              }
              
         }
        return ends;
}