c++ - How many decimal places does the primitive float and double support?

I have read that double stores 15 digits and float stores 7 digits.

My question is, are these numbers the number of decimal places supported or total number of digits in a number?

Answer

Those are the total number of "significant figures" if you will, counting from left to right, regardless of where the decimal point is. Beyond those numbers of digits, accuracy is not preserved.

The counts you listed are for the base 10 representation.