将字符与Java中的字符串数组中的元素进行比较

Question

public static int getDigit(char character, char letters[]  )
{
    int digit=0;
    for (int i=0;i<=0;i++);
    {
        for (int j=0; j<(letters[i].length());j++)
        {
            if (letters[i][j]==character)
            {
               digit=i; 
            }
        }    
    }
    return digit;
}

where array is LETTERS={("abc"),("def"),("ghi"),("jkl"), ("mno)"),("pqrs"),("tuv"),("wxyz")}; and character could be any alphabet.

I want program to find a character entered and to display the location of that in the string. Eg- If user enters letter "g" then it should display number 3 because it is in 3rd element of array.

Answer 1

Here is a working implementation of what you appear to want. I assume that your letters array is intended to be a 2D jagged character array. Your original code really only had a few minor issues, mainly in the loop logic.

public static int getDigit(char character, char letters[][]) {
    int digit = -1; // return -1 if character not found

    for (int i=0;i < letters.length; i++) {
        for (int j=0; j < letters[i].length; j++) {
            if (letters[i][j] == character) {
                digit = i;
                i = letters.length;
                break;
            }
        }    
    }

    return digit;
}

public static void main(String args[]) {
    char[][] letters = new char[][] {
        { 'a', 'b', 'c' },
        { 'd', 'e', 'f' },
        { 'g', 'h', 'i' },
        { 'j', 'k', 'l' },
        { 'm', 'n', 'o' },
        { 'p', 'q', 'r', 's' },
        { 't', 'u', 'v' },
        { 'w', 'x', 'y', 'z' }};
    System.out.println(getDigit('d', letters) );
}

Demo

Answer 2

It's not really possible to completely answer you question because it doesn't say what the problem is besides "it doesn't work".

Just skimming the code: you should probably change the line digit=i; to return i + 1; because you said it should return 3 if "g" is the third character.

Also, this loop is nonsense for (int i=0;i<=0;i++); It will run only once ever... Also as @bcsb1001 pointed out in the comments, the semicolon at the end of the loop essentially ends it, so the loop is actually empty! It should be for (int i=0;i<letters.length();i++) {

There might be other issues with this code. You didn't share enough.