Why was the decision made to separate data types into int and long?

The separation of int and long types was adopted to optimize memory usage and performance.

Main reasons:

• Size: int occupies 32 bits of memory, while long is 64 bits. Storing smaller integers with 32 bits is sufficient, and using 64 bits for such values would be an inefficient use of resources.
• Value Range: int can store values from -2,147,483,648 to 2,147,483,647. long supports a much larger range, approximately from -9 quintillion to 9 quintillion. This allows working with very large numbers when the int range is insufficient.
• Performance: Operations on 32-bit numbers (int) are generally faster for the processor than operations on 64-bit numbers (long), especially on older architectures. Using a more compact int type where possible improves performance.

Example usage:

// Using int for values within its range
int count = 1000;

// Using long for larger values exceeding int's range
long totalPopulation = 8_000_000_000L;