Where is error occured in this code?

Question

import java.util.Scanner;

public class Program
{
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
String text = scanner.nextLine();
char[] arr = text.toCharArray();
String rev=arr.length;
for(int i =rev-1;i>=0;i--)
{
rev+=arr.charAt(str(i));
System.Out.print(rev);
}
//your code goes here

}
}

Answer 1

There are multiple issues with your code. Probably because you seem to be mixing different strategies on reversing a string.

If you want to keep the input string split into an array of characters;

1. String rev = arr.length;
These are incompatible types. You're attempting to set an integer to a String variable. Instead use;
String rev = "";
2. rev-1 in your for loop. Here try;
arr.length-1 instead
3. In your loop you are attempting to get the charAt of an array. charAt() works with a String type. Just access the array by the index of i arr[i]
4. 'Out' should not be capitalized and the output should occur outside of and after the loop.
for (...; ...; ...) {
...
}
System.out.println(rev);

If you want to skip making the string into an array and just loop over it directly;

1. See step 1, 2, 4 above!
2. Remove the line that converts text to a char array.
3. Change arr.charAt(str(1)) to;
text.charAt(i);

Answer 2

Not quite, but it's closer.
Change;
rev+=text(i);
to
rev += arr[i];
And move System.out.println(rev);
So it is after the loops closing curly brace }.

Answer 3

String rev = ""; // not length here
int length = arr.length; // not String here

for (int i=length-1; i>=0; i--) { // not rev
//rev += arr.charAt( str(i) );
// charAt() is String method not usable for array
rev += arr[i];
// System.out.print(rev); // not here
}
System.out.print(rev); // not uppercase Out

Answer 4

import java.util.Scanner;

public class Program
{
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
String text = scanner.nextLine();
char[] arr = text.toCharArray();
String rev="";
for(int i =arr.length-1;i>=0;i--)
{
rev+=text(i);
System.out.println(rev);
}
//your code goes here

}
}
// this is correct or not