UNION

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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;

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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

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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• The structure variable has separate memory locations for each

members• Can access all members at a time

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age (2 bytes) name (5 bytes)

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• The union variable has only one memory locations for all

members• Can access only one member at a time

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name (5 bytes)