firstTry

/**
 * Created by mona on 4/30/16.
 */
public class NumberOfOnes {
    public int numSetBits(long a) {

        String binaryStr= Long.toBinaryString(a);
        int count=0;
        int len = binaryStr.length();
        if (len==1){
            if (String.valueOf(binaryStr.charAt(0))=="1"){
                return 1;
            }
            else return 0;
        }
        for (int i=0; i<len; i++){
            if (String.valueOf(binaryStr.charAt(i))=="1") {
                count++;
            }
        }
        return count;
    }
}