Need some help solving a code challenge (Camel to Snake) (Java)

Question

I'm getting all of the trials correct except the fifth one (it won't let me know what it is)
My code is below, I know it's messy I'm still pretty new to Java but I added some comments

import java.util.Scanner;
public class Program
{
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
char[] camel = sc.nextLine().toCharArray();
// original input

String fin = "";
// final string to be used

int x = 0;
// used to tell if the following code is the first instance or not

for (char i:camel){
if (Character.isUpperCase(i) && x>0){
fin+="_"+Character.toLowerCase(i);
}
// adds _c for C to final if its uppercase and not the first time

else {
fin+=i;
//adds original character

};
x++;
};
System.out.println(fin);
}
}

Answer 1

Here's an updated version of your code: 👇

import java.util.Scanner;

public class Program {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
char[] camel = sc.nextLine().toCharArray();
String fin = "";

int x = 0;

for (char i : camel) {
if (Character.isUpperCase(i)) {
if (x > 0) {
fin += "_";
}
fin += Character.toLowerCase(i);
} else {
fin += i;
}
x++;
}

System.out.println(fin);
}
}

Answer 2

It will also work. 👇

public final class CamelToSnake {
public static void main(String[] args) {
System.out.println(
new java.util.Scanner(System.in)
.nextLine()
.replaceAll("(?<=[^//b^])([A-Z])", "_$1")
.toLowerCase()
);
}
}