2. Union
• Union is same as the structure
• Like structure, union also contains members of
different data type
• Union can be declared using the keyword union
• Syntax: union unionname{
•
member 1;
•
member 2;
•
....
•
};
• Like structure a union variable can be declare
• Syn: union unionname variable list;
3. Union and Structure
• The memory space occupy for a union variable is
the size of largest member
• In structure each members has its own memory
locations
• In union all members shares a common memory
location
• In structure we can access all members at a time
• In union we can access only one member at a
time
4. Union and Structure
• Eg
• Stuct check
• {
int age;
char name[5];
• }s;
• The memory space of struct variable s=sum of size of all
members
• Ie sizeof(age)+sizeof(name)
• => 2+5 = 7 bytes age (2 bytes) name (5 bytes)
• The structure variable has separate memory locations for
each members
• Can access all members at a time
5. Union and Structure
• Eg
• union check
• {
int age;
char name[5];
• }u;
• The memory space of union variable s=size of largest
members
• Ie sizeof(name)
• => 5 = 5 bytes name (5 bytes)
• The union variable has only one memory locations for all
members
• Can access only one member at a time
