C Data Types
The following table shows the data types allowed in LabWindows/CVI.
| Type | Size | Minimum | Maximum |
|---|---|---|---|
| char | 8 | –128 | 127 |
| unsigned char | 8 | 0 | 255 |
| short | 16 | –32,768 | 32,767 |
| unsigned short | 16 | 0 | 65,535 |
| int; long int | 32 | –231 | 231 – 1 |
| __int64; long long | 64 | –263 | 263 – 1 |
| unsigned int | 32 | 0 | 232 – 1 |
| unsigned __int64; unsigned long long | 64 | 0 | 264 – 1 |
| unsigned long | 32 | 0 | 232 – 1 |
| float | 32 | –3.40282E+38 | 3.40282E+38 |
| double; long double | 64 | –1.79769E+308 | 1.79769E+308 |
| pointers (void *) | 32 (32-bit OSes) 64 (64-bit OSes) |
N/A | N/A |
| enum | 32 | –231 | 231 – 1 |
| size_t | 32 (32-bit OSes) 64 (64-bit OSes) |
0 (32-bit OSes) 0 (64-bit OSes) |
232 – 1 (32-bit OSes) 264 – 1 (64-bit OSes) |
| ssize_t | 32 (32-bit OSes) 64 (64-bit OSes) |
–231 (32-bit OSes) –263 |
231 – 1 (32-bit OSes) 263 – 1 |
| intptr_t | 32 (32-bit OSes) 64 (64-bit OSes) |
N/A | N/A |
| ptrdiff_t | 32 (32-bit OSes) 64 (64-bit OSes) |
N/A | N/A |
| uintptr_t | 32 (32-bit OSes) 64 (64-bit OSes) |
N/A | N/A |
In LabWindows/CVI, characters are signed, unless you explicitly declare them unsigned. The types float and double conform to 4-byte and 8-byte IEEE standard formats.