String reverse(String s) {
String result = "";
for (int i = s.length() - 1; i >= 0; i--) {
result = result + s.charAt(i);
}
return result;
}

reverse("hello")
reverse("Rava")

boolean isPalindrome(String s) {
String lower = s.toLowerCase();
int left = 0;
int right = lower.length() - 1;
while (left < right) {
if (lower.charAt(left) != lower.charAt(right)) {
return false;
}
left++;
right--;
}
return true;
}

isPalindrome("radar")
isPalindrome("hello")
isPalindrome("Racecar")

int countChar(String s, char c) {
int count = 0;
for (int i = 0; i < s.length(); i++) {
if (s.charAt(i) == c) count++;
}
return count;
}

countChar("mississippi", 's')
countChar("hello world", 'l')

String repeat(String s, int n) {
String result = "";
for (int i = 0; i < n; i++) {
result = result + s;
}
return result;
}

repeat("ab", 5)
repeat("*", 10)

%methods
%quit