Data Types
As explained in the Variables chapter, a variable in C must be a specified data type, and you must use a format specifier inside the printf() function to display it:
Example
// Create variables
int myNum = 5; // Integer (whole number)
float
myFloatNum = 5.99; // Floating point number
char myLetter = 'D'; //
Character
// Print variables
printf("%d\n", myNum);
printf("%f\n", myFloatNum);
printf("%c\n", myLetter);
Basic Data Types
The data type specifies the size and type of information the variable will store.
In this tutorial, we will focus on the most basic ones:
| Data Type | Size | Description | Example |
|---|---|---|---|
int |
2 or 4 bytes | Stores whole numbers, without decimals | 1 |
float |
4 bytes | Stores fractional numbers, containing one or more decimals. Sufficient for storing 6-7 decimal digits | 1.99 |
double |
8 bytes | Stores fractional numbers, containing one or more decimals. Sufficient for storing 15 decimal digits | 1.99 |
char |
1 byte | Stores a single character/letter/number, or ASCII values | 'A' |
Basic Format Specifiers
There are different format specifiers for each data type. Here are some of them:
| Format Specifier | Data Type | Try it |
|---|---|---|
%d or %i |
int |
|
%f or %F |
float |
|
%lf |
double |
|
%c |
char |
|
%s |
Used for strings (text), which you will learn more about in a later chapter |
Note: It is important that you use the correct format specifier for the specified data type. If not, the program may produce errors or even crash.
