Incompatible Types String and Char

Question

I\'m not sure why I\'m getting this error. I think the code in general is okay although I\'m sure there is a shorter way then using all the else ifs. The problem is it says

Answer 1

R2D2 is of type String while the single quotes around a character (as in 'a') makes it a character literal. Strings cannot be assigned, or compared to a, character. That's the reason.

There are two kinds of problems in the code.

1. `R2D2= lineOne.charAt(i); // a character being assigned to a String variable`

Solution: R2D2 = Character.toString(lineOne.charAt(i));

2. `if (R2D2== 'a'|| R2D2=='A')` //strings being compared with char literals.

Solution: if (R2D2.equals("a")|| R2D2.equals("A"))

FYI, To improved the maintenance you can also do.

if(R2D2.equalsIgnoreCase('a'))

Answer 2

char is not String. Declare R2D2 as char

char R2D2 = '';

To check vowel make a method like below and reuse this method at for loop and count the vowel occurrence:

static boolean isVowel(char ch) {
    ch = Character.toLowerCase(ch);
    if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u') {
        return true;
    }
    return false;
 }

Answer 3

    String lineOne,  R2D2 = "";

R2D2 is a string and you are comparing with a char if (R2D2== 'a'|| R2D2=='A')

try this

for (int i = word -1; i>= 0; i--) { R2D2= lineOne.charAt(i);

        if (R2D2=="a"|| R2D2=="A")
        count++;
        else if (R2D2=="e"||R2D2=="E")
        count++;
        else if (R2D2=="o"|| R2D2=="O")
        count++;
        else if (R2D2=="u"||R2D2=="U")
        count++;
        else if (R2D2=="y"||R2D2=="Y")
        count++;

}

One side not,you should compare using .equals() instead of ==

Answer 4

If you want to fix the long if chain you can do something like this:

if (anyOf(R2D2, "AaEeIiOoUuYy".toCharArray())

and later have:

private static boolean anyOf(char in, char[] items) {
    for (int i = 0; i < items.length; i++) {
        if (in == items[i])
            return true;
    }
    return false;
}