Example 1 Big O vs Big Theta

comparison.java

// Same worst case and best case
public static boolean detectCharacter(String s, char c)
{
  boolean hasCharacter = false;
  for(int i = 0; i < s.length(); i++) {
    if(s.charAt(i) == c) hasCharacter = true;
  }
  return hasCharacter;
}
// Different best case and worse case
public static boolean detectCharacter(String s, char c)
{
  for(int i = 0; i < s.length(); i++) {
    if(s.charAt(i) == c) return true;
  }
  return false;
}