Java > Warmup-1 >startOz (CodingBat Solution)

Problem:

Given a string, return a string made of the first 2 chars (if present), however include first char only if it is 'o' and include the second only if it is 'z', so "ozymandias" yields "oz".

startOz("ozymandias") → "oz"
startOz("bzoo") → "z"
startOz("oxx") → "o"

Solution:

public String startOz(String str) {
if ( str.length() == 1)
  str = str.substring(0,1);
  else if (str.length() == 0)
  str = "";
else if ( !(str.charAt(0) == 'o') && !(str.charAt(1) ==
  'z') )
   str = "";
   else if ( str.charAt(0) == 'o' && str.charAt(1) != 'z')
   str = str.substring(0,1);
   else if (str.charAt(1) == 'z' && str.charAt(0) != 'o')
   str = str.substring(1,2);
   else if ( str.charAt(0) =='o' && str.charAt(1) == 'z')
   str = str.substring(0,2);
   return str;
 
}