STRUCTURE:  PUTTING RELATED ITEMS TOGETHER

When writing a program, several variables (identifiers) are declared and used. Some of the names used as identifiers are related and can be grouped together (memory wise) in one location as one unit in memory. This grouping of related names, including several variables and functions is called a structure.   In C, structures group only variables, while in C++ structures group variables as well as their related functions. Each variable and function is referred to as a member of the structure. In C++, the bundling of variables and functions adds the important concept of Object Oriented Programming (OOP), also known as class, to the C language.  This incorporation of variables and functions makes C++ both a Procedural as well Object-Oriented language.

HOW TO CREATE A STRUCTURE IN C

The key word struct is used to create a structure. In C, there are three general formats to create a structure variable as shown in Figures 7.1a, b, and c. Notice in Figure 7.1a, the structure is defined with the use of a tag name followed by the definition of the structure and the actual structure variable name. In Figure 7.1b, the use of a tag name is eliminated and the rest of the definition and the structure declaration remain the same.