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Union is a user-defined data type that is used to hold the different types of elements like structure. In union, all members share the same memory location.
Syntax:
0 1 2 3 4 5 6 7 8 | union [union name] { member definition; member definition; ... member definition; }; |
Example
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | #include <stdio.h> union employe{ //defining a union int id; char name[32]; float salary; } uemp; struct structure_emp{ char name[32]; float salary; } sJob; int main() { printf("size of union = %d", sizeof(uemp)); printf("\nsize of structure = %d", sizeof(sJob)); return 0; } |
Output
0 1 2 3 | size of union = 32 size of structure = 36 |
Difference between C structure and C union
| C Structure | C Union |
| It allocates storage space for all its members separately. | It allocates one common storage space for all its. |
| It occupies height memory space. | It occupies lower memory space over the structure. |
| All the member can be accessed at a time | Only one member can be accessed at a time |
| Example: struct employe { int id; char name[40]; float salary; }; | Example: union employe { int id; char name[40]; float salary; }; |
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