C Pointers Lecture Notes

What are Pointers?

• A pointer is a variable that stores the memory address of another variable.
• Pointers are crucial in C programming for efficient data manipulation and memory management.

Creating Pointers

• Use the & operator to get the memory address of a variable.
• Syntax: int myAge = 43; // an int variable printf("%p", &myAge); // Outputs the memory address of myAge
• A pointer variable is created using the * operator: int* ptr = &myAge; // A pointer variable storing the address of myAge

Dereference Operator (*)*

• The * operator is used to dereference a pointer, accessing the value stored at the address.
• Example: printf("%d\n", *ptr); // Outputs the value of myAge (43)
• Note: * in declaration creates a pointer, elsewhere it dereferences a pointer.

Importance of Pointers

• Pointers allow manipulation of data stored in memory, reducing code complexity and improving performance.
• Essential for implementing complex data structures like lists, trees, and graphs.
• Required for file handling and memory management.

Syntax and Declaration

• Two ways to declare pointer variables: int* myNum; int *myNum;

C Pointers vs. Other Languages

• Pointers are unique to C and not typically found in languages like Python and Java.
• They provide C with powerful capabilities for direct memory manipulation.

Usage Warning

• Pointers should be handled with care to avoid damaging data in other memory addresses.

Additional Information

• Pointers are extensively used in C for operations that involve memory management, file handling, and data structure implementations.
• Links between sections: Memory Management, File Operations.