Example: Array Equality Check (memcmp) in C

// Array Equality Check (memcmp)
#include <stdio.h>
#include <string.h>  // For memcmp
#include <stdbool.h> // For using bool type

// Function to compare two character arrays (strings) for equality using memcmp
bool areCharArraysEqualMemcmp(const char arr1[], size_t size1, const char arr2[], size_t size2) {
    // Step 1: Check if the sizes of the arrays are different
    if (size1 != size2) {
        return false; // Arrays cannot be equal if their sizes differ
    }

    // Step 2: Use memcmp to compare the memory blocks
    // memcmp returns 0 if the blocks are identical
    return memcmp(arr1, arr2, size1) == 0;
}

// Example for integer arrays (with a caveat)
bool areIntArraysEqualMemcmp(const int arr1[], size_t size1, const int arr2[], size_t size2) {
    if (size1 != size2) {
        return false;
    }
    // memcmp compares byte-by-byte. This works for simple integer arrays
    // but be cautious with structs, padding, or cross-platform comparisons.
    return memcmp(arr1, arr2, size1 * sizeof(int)) == 0;
}


int main() {
    // Example 1 (Char Arrays): Equal
    char str1[] = "hello";
    size_t len1 = strlen(str1); // Excludes null terminator for comparison of content

    char str2[] = "hello";
    size_t len2 = strlen(str2);

    // Example 2 (Char Arrays): Unequal
    char str3[] = "world";
    size_t len3 = strlen(str3);

    // Example 3 (Int Arrays): Equal
    int intArr1[] = {1, 2, 3, 4, 5};
    size_t intSize1 = sizeof(intArr1) / sizeof(intArr1[0]);

    int intArr2[] = {1, 2, 3, 4, 5};
    size_t intSize2 = sizeof(intArr2) / sizeof(intArr2[0]);

    // Example 4 (Int Arrays): Unequal (different element)
    int intArr3[] = {1, 2, 3, 4, 99};
    size_t intSize3 = sizeof(intArr3) / sizeof(intArr3[0]);

    printf("Comparing char arrays \"%s\" and \"%s\": %s\n", str1, str2, areCharArraysEqualMemcmp(str1, len1, str2, len2) ? "Equal" : "Not Equal");
    printf("Comparing char arrays \"%s\" and \"%s\": %s\n", str1, str3, areCharArraysEqualMemcmp(str1, len1, str3, len3) ? "Equal" : "Not Equal");

    printf("Comparing int arrays {1,2,3,4,5} and {1,2,3,4,5}: %s\n", areIntArraysEqualMemcmp(intArr1, intSize1, intArr2, intSize2) ? "Equal" : "Not Equal");
    printf("Comparing int arrays {1,2,3,4,5} and {1,2,3,4,99}: %s\n", areIntArraysEqualMemcmp(intArr1, intSize1, intArr3, intSize3) ? "Equal" : "Not Equal");

    return 0;
}