Programming in Objective-C, Sixth Edition

Data Types and Constants

You have already encountered the Objective-C basic data type int. As you will recall, a variable declared to be of type int can be used to contain integral values only—that is, values that do not contain decimal digits.

The Objective-C programming language provides three other basic data types: float, double, and char. A variable declared to be of type float can be used for storing floating-point numbers (values containing decimal digits). The double type is the same as type float, typically with roughly twice the range. The char data type can be used to store a single character, such as the letter a, the digit character 6, or a semicolon (more on this later).

In Objective-C, any literal number, single character, or ...