Structure Declarations

Structures are used to declare new types. Structures are several variables bundled together into a single package.

We can use structure to represent more complex data types. For example to represent a point in 2D space we could create a structure called point that packs together two float (decimal) values called x and y. To declare structures we can use the struct keyword in conjunction with the typedef keyword. Our declaration would look like this.

typedef struct {
  float x;
  float y;
} point;

We should place this definition above any functions that wish to use it. This type is no different to the built in types, and we can use it in all the same ways. To access an individual field we use a dot ., followed by the name of the field, such as x.

point p;
p.x = 0.1;
p.y = 10.0;
float length = sqrt(p.x * p.x + p.y * p.y);