Structure Vs Union

What is a Structure?

A Structure in C/C++ lets you group variables of different types into a single unit. Each member stores its value in its own memory space, and you can access them independently.

What is a Union?

A Union in C/C++ lets multiple variables share the same memory location. It stores one member value at a time because all members overlap in memory.

What are the key differences between Structure and Union?

– **Memory Allocation:** In a Structure, each member occupies its own memory location. In a Union, all members share the same memory space.
– **Size:** A Structure’s size equals the total size of all its members. A Union’s size equals the size of its largest member.
– **Usage:** Use Structures to store multiple related values simultaneously. Use Unions to store one value at a time, saving memory.
– **Access:** Structures let you access all members independently. Unions allow access to only one member at a time since modifying one affects others.

What are the advantages of using a Structure?

– Structures let you group related variables of different types.
– Each member preserves its value independently in its own memory.
– Structures suit applications that need complex data models, such as records or objects.

What are the advantages of using a Union?

– Unions save memory by letting multiple variables share the same memory.
– Unions work best when only one value needs storage at a time.
– You can use Unions in embedded systems and other memory-constrained environments.

How do you declare a Structure in C?


struct Example {
    int a;
    float b;
    char c;
};


How do you declare a Union in C?


union Example {
    int a;
    float b;
    char c;
};


Which is better: Structure or Union?

Your choice depends on the use case. Use a Structure to store and access multiple values simultaneously. Use a Union to optimize memory when only one value is required at a time.