C Language Variable Types
Part of the Beginning C Programming For Dummies Cheat Sheet
Rather than make all your variables floats, it’s more efficient to examine the type of data that’s stored and then choose an appropriate C variable type.
|_Bool||0 to 1|
|char||–28 to 127|
|unsigned char||0 to255|
|short int||–32,768 to 32,767|
|unsigned short int||0 to 65,535|
|int||–2,147,483,648 to 2,147,483,647|
|unsigned int||0 to 4,294,967,295|
|long int||–2,147,483,648 to 2,147,483,647|
|unsigned long int||0 to 4,294,967,295|
|float||1.17×10–38 to 3.40×1038|
|double||2.22×10–308 to 1.79×10308|
Keep these C language variable type points in mind:
Ensure that you choose the proper variable type for the values you need to store.
The _Bool type stores only two values, 0 and 1, which can represent TRUE or FALSE or On or Off or any binary condition.
The char variable type stores character values, though it can also be used to store tiny integers.
Integers, or whole numbers, are stored in the int variable types.
Any type of value, from the very large to the very small, and any fractional values are stored in the float and double types.
Remember to use int values for functions that generate integers, such as getchar(). It’s easy to assume that the function returns a char value because of the function’s name.
C lacks a string variable type. Instead, an array of char variables is used.
Other variable types include structures and pointers.