Example Code Ch 12-4
The following recursive method recognizes whether a String parameter consists of a specific pattern and returns true if the String has that pattern, false otherwise.
public boolean patternRecognizer(String a)
{
if (a == null) return false;
else if (a.length() == 1 || (a.length() == 2
&& a.charAt(0) == a.charAt(1)))
return true;
else if )
return false;
else if )
return patternRecognizer);
else return false;
}
-Refer to Example Code Ch 12-4: If the method is called as patternRecognizer(x) where x = "aa", what will the result be?
A) true
B) false
C) NullPointerException
D) a run-time error
E) infinite recursion

Question

Quizplus · Accepted Answer

The method first checks if the input string is null or has length 1 or 2 with the same characters. Since "aa" satisfies the second condition, the method returns true.