startOz

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".


Test Cases: 

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

Solution:

public String startOz(String str) {
 String result = "";
 
  if (str.length() >= 1 && str.charAt(0)=='o') {
    result = result + str.charAt(0);
  }
 
  if (str.length() >= 2 && str.charAt(1)=='z') {
    result = result + str.charAt(1);
  }
 
  return result;
}