C++ has multiple integer types — choose by size needed:
| Type | Size | Range |
|------|------|-------|
| short | 16-bit | -32,768 to 32,767 |
| int | 32-bit | ~-2 billion to 2 billion |
| long | 32 or 64-bit | platform dependent |
| long long | 64-bit | ~-9 quintillion |
| unsigned int | 32-bit | 0 to ~4 billion |
sizeof() tells you the actual size in bytes.