Write a method that counts the number of enabled bits in an Integer.

Question

Anonymous · Accepted Answer

The bits question was a particularly hard for me because I had never done bit manipulation before.

GuyWhoAnswersRandomQuestionsOnInternet · Answer

Bit manipulation can be tricky because it isn't done that often. Here is a pretty simple function that should work as a solution to this problem:

	public static int chkEnabledBits(int chkInt)
	{
		int numEnabledBits = 0;
		
		while(chkInt > 0)
		{
			numEnabledBits += chkInt&1;
			chkInt = chkInt >> 1;
		}
		
		return numEnabledBits;
	}

GuyWhoRespondsToRandomQuestionsOnInternet · Answer

The previous answer forgot about negative numbers! :( Java represents integers in two's compliment. Here's a simple albeit hacky solution:

public static int chkEnabledBits(int chkInt)
{
	int numEnabledBits = 0;
	int numChkedBits = 0;
	while( (chkInt != 0) && (numChkedBits > 1;
		numChkedBits++;
	}
	return numEnabledBits;
}

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