A nanosecond is one-billionth of a second.

A native data type is one that is defined in the C++ language, as opposed to a user defined data type (class).

The new operator is used to allocate memory for variables of the dynamic storage class; these are variables whose storage requirements aren't known until the program is executing.

Nondisplay character; see nonprinting character.

A nonmember function is one that is not a member of a particular class being discussed, although it may be a member function of another class.

A nonnumeric variable is a variable that is not used in calculations like adding, multiplying, or subtracting. Such variables might represent names, addresses, telephone numbers, Social Security numbers, bank account numbers, or drivers license numbers. Note that just because something is called a number or even is composed entirely of the digits 0-9, does not make it a numeric variable by our standards; the question is how the item is used. No one adds, multiplies, or subtracts drivers license numbers, for example; they serve solely as identifiers, and could just as easily have letters in them, as indeed some of them do.

A nonprinting character is used to control the format of our displayed or printed information, rather than to represent a particular letter, digit, or other special character. The space ( ) is one of the more important nonprinting characters.

A null byte is a byte with the value 0, commonly used to indicate the end of a C string. Note that this is not the same as the character '0', which is a normal printable character having the ASCII code 48.

A null object is an object of some (specified) class whose purpose is to indicate that a "real" object of that class does not exist, analogously to a null pointer. One common use for a null object is as a return value from a member function that is supposed to return an object with some specified properties but cannot find such an object. For example, a null StockItem object might be used to indicate that an item with a specified UPC cannot be found in the inventory of a store.

A null pointer is a pointer with the value 0. This value is particularly suited to indicate that a pointer isn't pointing to anything at the moment, due to some special treatment of zero-valued pointers built into the C++ language.

A numeric variable is a variable representing a quantity that can be expressed as a number, whether a whole number (an integer variable), or a number with a fractional part (a floating-point variable), and which can be used in calculations such as addition, subtraction, multiplication, or division. The integer variable types in C++ are char, short, int, and long. Each of these types can be further subdivided into signed and unsigned versions; the former of these can represent both negative and positive values (and 0), whereas the latter can represent only positive values (and 0), but provides a greater range of positive values than the corresponding signed version does. The floating-point variable types are float and double, which differ in their range and precision. Unlike the integer variable types, the floating-point types are not divided into signed or unsigned versions; all floating-point variables can represent either positive or negative numbers as well as 0; see the individual headings float and double for details on range and precision.

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