Functions and Pointers
Section 2: Functions and Pointers
Lesson 1: Functions in C
1.1 Defining and Calling Functions
Functions in C allow you to break down a program into smaller, manageable pieces. They consist of a function declaration and definition.
Example (Function Definition and Call):
#include <stdio.h>
// Function declaration
void greet() {
printf("Hello, there!\n");
}
int main() {
// Function call
greet();
return 0;
}
1.2 Parameters and Return Values
Functions can accept parameters (inputs) and return values (outputs). Parameters enable the passing of data into functions, and return values allow functions to provide results.
Example (Function with Parameters and Return Value):
#include <stdio.h>
// Function declaration with parameters and return value
int add(int a, int b) {
return a + b;
}
int main() {
// Function call with arguments and capturing the result
int result = add(3, 4);
// Displaying the result
printf("Sum: %d\n", result);
return 0;
}
Lesson 2: Introduction to Pointers
2.1 Understanding Pointers and Memory Addresses
Pointers in C are variables that store memory addresses. They provide a way to work directly with memory, offering flexibility and efficiency.
Example (Pointers and Memory Addresses):
#include <stdio.h>
int main() {
int num = 42;
// Pointer declaration and assignment
int *ptr = #
// Displaying the memory address and value using the pointer
printf("Memory Address: %p\n", (void *)ptr);
printf("Value: %d\n", *ptr);
return 0;
}
2.2 Pointer Arithmetic
Pointer arithmetic allows you to perform arithmetic operations directly on pointers, making it useful for traversing arrays and managing memory.
Example (Pointer Arithmetic):
#include <stdio.h>
int main() {
int numbers[] = {1, 2, 3, 4, 5};
// Pointer to the first element of the array
int *ptr = numbers;
// Accessing array elements using pointer arithmetic
for (int i = 0; i < 5; i++) {
printf("Element %d: %d\n", i, *(ptr + i));
}
return 0;
}
Understanding functions and pointers is crucial for developing more complex and modular C programs. Practice defining and calling functions with various parameters and return values. Explore the use of pointers for efficient memory management and manipulation.