# Using Efficient Data Types

In cases where more than one data type can be used for a variable, consider selecting the data types based on the following hierarchy, listed from most to least efficient:

- char

- short

- int

- long

- long long

- float

- double

- long double

### Note

In an arithmetic expression, you should avoid mixing integer and floating-point data.

You can use integer data types (int, int long, etc.) in loops to improve floating point performance. Convert the data type to integer data types, process the data, then convert the data to the old type.

Parent topic: Overview: Tuning Performance