1. Basics of Structures
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| A structure is a collection of related variables (of possibly different types) grouped together under a single name. This is a an example of composition–building complex structures out of simple ones. |
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| Examples |
struct point {
int x;
int y;
};
// notice the ; at the end
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struct student {
char name[64];
int id;
int age;
};
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 A struct declaration defines a type. |
The name of the structure is optional
struct { ... } x, y, z; |
| The variables declared within a structure are called its members. |
Variables can be declared like any other built in data-type.
struct point pt; |
Initialization is done by specifying values of every member.
struct point pt={10, 20}; |
| Assignment operator copies every member of the structure (be careful with pointers). |
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| Members can be structures |
struct triangle {
struct point ptA;
struct point ptB;
struct point ptC;
};
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| Members can be self referential |
struct element {
int data;
struct element *next;
}
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| Individual members can be accessed using ‘.’ operator. |
struct point pt={10, 20};
int x=pt.x; int y=pt.y;
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| If structure is nested, multiple ‘.’ are required |
struct rectangle
{
struct point tl; /∗ top left ∗/
struct point br; /∗ bottom right ∗/
};
struct rectangle rect ;
int tlx= rect.tl.x; /∗ nested ∗/
int tly= rect.tl.y;
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