asked on

string concatenation challenge

Hi,

I am working on below challenge
http://codingbat.com/prob/p117334

I wrote as below

public String stringSplosion(String str) {
  String s="";
  for(int i=0;i<=str.length()-1;i++){
  return (s+str.substring(i));
  
  }
  return null;
}

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My test cases failing as below

Expected      Run
stringSplosion("Code") → "CCoCodCode"      "Code"      X
stringSplosion("abc") → "aababc"      "abc"      X
stringSplosion("ab") → "aab"      "ab"      X
stringSplosion("x") → "x"      "x"      OK
stringSplosion("fade") → "ffafadfade"      "fade"      X
stringSplosion("There") → "TThTheTherThere"      "There"      X
stringSplosion("Kitten") → "KKiKitKittKitteKitten"      "Kitten"      X
stringSplosion("Bye") → "BByBye"      "Bye"      X
stringSplosion("Good") → "GGoGooGood"      "Good"      X
stringSplosion("Bad") → "BBaBad"      "Bad"      X

How do i fix and improve my code. Please advise

SOLUTION

n2fc

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ASKER CERTIFIED SOLUTION

krakatoa

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n2fc

Yet another solution (a tad more arcane):

public String stringSplosion(String str) {
   String s="";
   for(int i=0; i<str.length(); s+=str.substring(0, ++i));
   return s;
}

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krakatoa

And one more, slightly better incremental model :

public String stringSplosion(String str) {

StringBuilder sb = new StringBuilder();

for(int y=0;y<str.length();y++){sb.append(str.substring(0,y+1));}

return sb.toString();
  }

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gudii9

ASKER

some reason stringbuilder is not coming to mind.

Let me read these solutions more detail once i get more time

krakatoa

StringBuilder is useful so yes do read the lit on it.

SOLUTION

awking00

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