Programming Techniques DT143G Lecture 10

Programmeringsteknik DT143G Lecture 10: Struct and Pointers

• Lecture was given on 05-12-2024 by Pascal Rebreyend
• Topics covered included structs, bit fields, their importance, and their connections with pointers.
• Struct definition and usage are crucial for managing complex, heterogeneous data.
• Struct definitions allow combining different data types in a single variable.
• Arrays store elements of the same data type; structs store elements of potentially different data types.
• Code examples were given using stdio.h and demonstrated how to define structs, access members, and display information using the dot operator.
• typedef allows for creating new data types that are convenient to use.
• Code was presented for handling and manipulating struct elements in C.

Usages of Structs

• Structures are convenient for database-like software.
• Arrays of structs can be created.
• One or more fields inside a struct can be pointers.
• Pointers to structs or arrays of structs provide flexibility to create complex data structures.
• Data structures can be designed to be as complex as needed using pointer structures.

Typedef and Functions

• Code examples demonstrated typedef and functions using structs.
• Code showed functions that accept or return struct variables.
  • Functions such as display and copypandmod
• Syntax for accessing struct members using the dot operator is essential for working with structs and their functions.

Struct and Dynamic Arrays

• Code demonstrated how to create dynamic arrays of structs.
• Functions like calloc and malloc to allocate memory for struct arrays are critical.
• Code examples demonstrated proper memory management using free for arrays of structs.

Bit Fields

• Code snippet demonstrated usage of bit fields for efficiency.
• Bit fields allow storing binary flags and bit-level values effectively.

Example: List

• A list is a collection of elements where each element points to the next.
• Lists provide functionality for inserting or removing elements.
• A special value, NULL, for pointers signifies the absence of a link.
• Linked lists, an important data structure, are used in many applications.

Example: A List

• Code examples for creating, adding, and displaying elements in a list.
• Using malloc for dynamically allocating elements in the list.
• Essential functions for list operations like list_add and display_list.

List and their Usages

• Using only one pointer to access elements effectively.
• Adding, removing, and manipulating list elements.

Conclusion

• Using structs allows grouping different types of information into a single variable.
• Features like unions and bit fields (not covered in the current session) facilitate low-level programming.
• Using pointers in combination with structs provides a powerful and flexible approach to creating and manipulating data.