Q13. Explain the function and usage of a union giving an example.
Ans. A union is a memory location that is shared by two or more different variables, generally of different types at different times. Defining a union is similar to defining a structure. Following declaration declares a union share having two variables (integer and character type) and creates a union object cnvt of union type share:
union share cnvt;
the keyword union is used for declaring and creating a union cnvt, both integer I and character ch share the same memory location. (of course, i (being integer) occupies 2 bytes and ch (being character) uses only 1 byte.
At any point, you can refer to the data stored in a cnvt as either an integer or a character. To assign the integer 20 to element i of cnvt, write
cnvt.i = 20;
To print the value of element ch of cnvt, write