Recursion

AP Computer Science A· difficulty 4/5

public static boolean isPal(String s) {
    if (s.length() <= 1) return true;
    if (s.charAt(0) != s.charAt(s.length() - 1)) return false;
    return isPal(s.substring(1, s.length() - 1));
}
System.out.println(isPal("racecar"));

What is printed?

A
$true$
check_circle
B
$false$
C
$Compile-time error$
D
$Runtime error$

Explanation

"racecar" reads the same forward and backward; recursion strips outer chars until base case.

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