The length of an integer

Question

Hello.
Just for couriosity I'd like to calculate the length of an int and by that I mean return the number of digits.
I know how to do this 'manually', but is there a method somewhere that looks a bit like this:
object.calcInt(47653);//returns 5Thanks in advance

Answer 1

Interesting. Nobody likes the log method even though it is 30% faster.
public class Garbage
    public static final int FIRST_INT = Integer.MAX_VALUE - 10000;
    public static final int LAST_INT  = Integer.MAX_VALUE;
    public static final int TESTS = 1000;
    public static void main(String args[])
        long divideTestTime = 0;
        long stringTestTime = 0;
        long logTestTime = 0;
        DivideTest divideTest = new DivideTest();
        StringTest stringTest = new StringTest();
        LogTest logTest = new LogTest();
        for (int i = 0; i < TESTS; i++)
                divideTestTime += runTest(divideTest);
                stringTestTime += runTest(stringTest);
                logTestTime += runTest(logTest);
        System.out.println("Divide-test Time: " + divideTestTime);
        System.out.println("String-test Time: " + stringTestTime);
        System.out.println("Log-test Time: " + logTestTime);
    public static long runTest(Test test)
        long start = System.currentTimeMillis();
        for (int i = FIRST_INT; i < LAST_INT; i++)
                test.lengthOf(i);
        return System.currentTimeMillis() - start;
interface Test {
    public int lengthOf(int i);
class DivideTest implements Test {
    public int lengthOf(int i) {
        int size = 0;
        do {
            size++;
            i /= 10;
        } while(i > 0);
        return size;
class StringTest implements Test {
    public int lengthOf(int i) {
        return String.valueOf(i).length();
class LogTest implements Test
    private static final double l210 = Math.log(10);
    public int lengthOf(int i) {
        return (int)(1 + (Math.log(0.5 + i) / l210));
}