Thread: Comparing using String.valueOf() method

I'm working on a program where I need to check if a number is a multiple of 5.
For my approach, I made a method that converts the int number to an array of digits and is supposed to compare the string value of the last digits of the array with 5 or 0. If it is equal, it is a multiple of 5. But doing so, do not work? Is there an issue with my code or is there an explanation for that?


Here is the method I made :

// check if number is multiple of five
    public static boolean isMultipleFive(int number) {
        boolean check = false;
 
        // convert number to an array of digits
        String temp = Integer.toString(number);
        int[] newGuess = new int[temp.length()];
        for (int i = 0; i < temp.length(); i++) {
            newGuess[i] = temp.charAt(i) - '0';
        }
 
        // System.out.println(Arrays.toString(newGuess)); // return [5, 0]
        // System.out.println(newGuess[newGuess.length - 0]); // return 0
 
        if (String.valueOf(newGuess[newGuess.length - 1]) == "5"
                || String.valueOf(newGuess[newGuess.length - 1]) == String.valueOf(0)) {
            check = true;
        }
 
        return check;
    }

When I test it with the following line (within the driver code) :

System.out.println(isMultipleFive(50)); // return false, why?

    public static boolean isMultipleFive(int number) {
        String temp = ""+number;
        char c = temp.charAt(temp.length()-1);
        return c == '5' || c == '0';
    }

--- Update ---

you cannot compare 2 strings with ==.
use .equals

    public static boolean isMultipleFive2(int number) {
        boolean check = false;
        String temp = Integer.toString(number);
        int[] newGuess = new int[temp.length()];
        for (int i = 0; i < temp.length(); i++) {
            newGuess[i] = temp.charAt(i) - '0';
        }
        if (String.valueOf(newGuess[newGuess.length - 1]).equals("5")
                || String.valueOf(newGuess[newGuess.length - 1]).equals(String.valueOf(0))) {
            check = true;
        }
 
        return check;
    }