Basic Data types and variables
- computer programs usually store data items, e.g. values representing age, height or weight of a student, temperature of a place, length of a wire, area of a land, volume of a water tank.
- variables are used in programs to store such values
- each variable has a type
- e.g. age is usually recorded as a discrete number i.e. 24, grade may be represented as a single character
- to use a variable it should be declared first
- variable declaration is a statement of the following format
data_type name_of_variable;
- For example a variable of type integer having name age can be declared as
- variables may be given an initial value when they are declared e.g.
Following table displays basic data types available in c, and the amount of memory they reserve
| Type |
size in bytes |
| char |
1 |
| short |
2 |
| int |
4 |
| long |
8 |
| float |
4 |
| double |
8 |
- the above table may be verified by executing this program which uses
sizeof operator