Floating-Point Types

Like ANSI C, C++ has three floating-point types: float, double, and long double. These types are described in terms of the number of significant figures they can represent and the minimum allowable range of exponents. Significant figures are the meaningful digits in a number. For example, writing the height of Mt. Shasta in California as 14,179 feet uses five significant figures, for it specifies the height to the nearest foot. But writing the height of Mt. Shasta as about 14,000 feet tall uses two significant figures, for the result is rounded to the nearest thousand feet; in this case, the remaining three digits are just placeholders. The number of significant figures doesn’t depend on the location of the decimal point. ...

Get C++ Primer Plus now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.