2. Array Declaration and Initialization

2.1 Basic Array Declaration

Python vs C Comparison:

C Array Declaration Syntax:

data_type array_name[size];
data_type array_name[size] = {value1, value2, ...};

2.2 Different Initialization Methods

2.2.1 Complete Initialization

int numbers[5] = {10, 20, 30, 40, 50};
char vowels[5] = {'a', 'e', 'i', 'o', 'u'};
float prices[3] = {12.5, 25.0, 8.75};

2.2.2 Partial Initialization

int scores[10] = {95, 87, 92};  // First 3 elements initialized
                                 // Remaining 7 elements = 0
char grades[5] = {'A', 'B'};     // grades[0]='A', grades[1]='B'
                                 // grades[2]=grades[3]=grades[4]='\0'

2.2.3 Size Inference

int data[] = {1, 2, 3, 4, 5};    // Size automatically becomes 5
char message[] = "Hello World";   // Size becomes 12 (including '\0')

2.2.4 Zero Initialization

int zeros[100] = {0};            // All elements initialized to 0
char buffer[50] = "";            // All characters initialized to '\0'

2.2.5 Uninitialized Arrays (Dangerous!)

int uninitialized[10];           // Contains garbage values!
// Always initialize arrays before use

2.3 Array Size and Memory

Understanding Array Size:

int numbers[5];                  // 5 integers × 4 bytes = 20 bytes
char name[20];                   // 20 characters × 1 byte = 20 bytes
double values[10];               // 10 doubles × 8 bytes = 80 bytes

// Getting array size at compile time
int size = sizeof(numbers) / sizeof(numbers[0]);  // Result: 5

Python vs C Size Operations: