Size of structure and padding concept Dry Run in C

Size of structure and padding concept is an interactive C dry run visualizer from the Structures programs section. Study the source code, then use the execution controls to follow each step, variable update, highlighted line, and console output.

This page provides a browser-based dry run with source-code highlighting, auto-scroll, voice narration controls, and execution output for learning the program step by step.

Size of structure and padding concept Program Code

#include <stdio.h>

struct Example1 {
    char c;    // 1 byte
    int i;     // 4 bytes
}; // Typically 8 bytes (1 + 3 padding + 4)

struct Example2 {
    int i;     // 4 bytes
    char c;    // 1 byte
}; // Typically 8 bytes (4 + 1 + 3 padding)

struct Example3 {
    char c1;   // 1 byte
    char c2;   // 1 byte
    int i;     // 4 bytes
}; // Typically 8 bytes (2 + 2 padding + 4)

struct Example4 {
    char c;    // 1 byte
    double d;  // 8 bytes
}; // Typically 16 bytes (1 + 7 padding + 8)

int main() {
    printf("Size of Example1: %lu bytes\n", sizeof(struct Example1));
    printf("Size of Example2: %lu bytes\n", sizeof(struct Example2));
    printf("Size of Example3: %lu bytes\n", sizeof(struct Example3));
    printf("Size of Example4: %lu bytes\n", sizeof(struct Example4));
    
    printf("\n--- Address demonstration ---\n");
    struct Example1 ex1;
    printf("Address of ex1.c: %p\n", (void*)&ex1.c);
    printf("Address of ex1.i: %p\n", (void*)&ex1.i);
    printf("Difference: %lu bytes\n", (char*)&ex1.i - (char*)&ex1.c);
    
    return 0;
}

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