Interview Question for Software Engineer - New Grad at Google:

public void printHex(int d) {
    string s = "";
    int m = 0;
    int next = d;
    int a[16];
    a[10] = "a";
    a[11] = "b";
    a[12] = "c";
    a[13] = "d";
    a[14] = "e";
    a[15] = "f";

    while (next > 15) {
        m = next % 16;
        if (m > 9 && m < 16)
            s = a[m] + s;
        else
            s = m + s;

        next = next / 16;
    }
   system.out.println(s);
}

B's answer doesn't work. I think a quick fix (besides all of the issues like incorrect array initialization, setting int to string, etc) would be to change while loop to a do while and the conditional to next > 0. Here is a generic solution passing radix which also handles negative numbers:

    public static String intToStr(int val, int radix) {

        char[] digits = new char[36];

        for (int i = 0; i < 10; i++) {
            digits[i] = (char)('0' + i);
        }
        for (int i = 10; i < 36; i++) {
            digits[i] = (char)('A' + i);
        }

        String result = "";
        boolean negative = false;
        if (val < 0) {
            negative = true;
        }
        val = Math.abs(val);

        do {
            result = digits[val%radix] + result;
            val = val/radix;
        } while (val != 0);

        if (negative) {
            result = "-" + result;
        }
        return result;
    }

String buffer = new StringBuffer();
while (n > 0) {
    int base = n% 16;
    buffer.append((base<10 ? base : (Char)('a'+base-10));
    n /= 16;
}
String result = buffer.toString().reverse();