Structures and Unions

struct groups related fields; union lets several fields share the same memory.

Easy

typedef struct {
    uint8_t  id;
    float    temperature;
    uint32_t timestamp;
} Reading;

Reading r = { .id = 1, .temperature = 24.5f };
r.timestamp = 1000;

union Word { uint32_t value; uint8_t bytes[4]; };   // view the same 4 bytes two ways

A struct's size can be larger than the sum of its fields because of padding for alignment. Unions are used for protocol parsing and type punning (byte order matters!).

Sub-topics (1)

Bit Fields

Pack several small values into the bits of one integer inside a struct.

Intermediate♥ 0🔖 0💬 0

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Sub-topics (1)

Bit Fields

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