C Program to Copy a String using strcpy() Function

C Programming mein strings ke saath kaam karna thoda tricky ho sakta hai kyunki C mein "String" naam ka koi inbuilt data type nahi hota, balki yeh Character Arrays hote hain. Aaj ke is detailed guide mein hum seekhenge ki kaise ek string ko dusri string mein copy kiya jata hai strcpy() library function ka upyog karke.

String Copying Kya Hai? (What is String Copying?)

String copying ka matlab hai ek existing character array (source) ke saare contents ko dusre character array (destination) mein transfer karna. Is process mein Null character (\0) ka bahut bada role hota hai, jo string ke end ko darshata hai.

The strcpy() Library Function

C language mein <string.h> header file humein strcpy() function provide karti hai. Iska syntax niche diya gaya hai:

char* strcpy(char* destination, const char* source);

Complete C Program (Source Code)

Niche ek detailed program diya gaya hai jo user se input leta hai aur use copy karta hai:

#include <stdio.h>
#include <string.h>
#include <conio.h>

int main() {
    char source[1000], destination[1000];

    // User se input lena
    printf("Enter the source string: ");
    gets(source); // Aap scanf ya fgets ka bhi use kar sakte hain

    // strcpy function ka upyog karke copy karna
    strcpy(destination, source);

    // Output dikhana
    printf("\n--- Result ---\n");
    printf("Source String: %s\n", source);
    printf("Destination String: %s\n", destination);

    return 0;
}

How This Program Works (Logic Explanation)

1. Header Files: Humne stdio.h basic input/output ke liye aur string.h strcpy() function ke liye use kiya hai.
2. Memory Allocation: Do character arrays source aur destination banaye gaye hain jinki capacity 1000 characters ki hai.
3. Copying Process: strcpy function source string ke pehle character se shuru karta hai aur tab tak copy karta hai jab tak use NULL (\0) nahi mil jata.

Common Errors in String Copying

Naye programmers aksar kuch galtiyan karte hain:

• Buffer Overflow: Agar destination array ka size source se chhota hai, toh program crash ho sakta hai.
• Assignment Operator: C mein aap destination = source; nahi likh sakte, aapko hamesha function ka use karna hoga.

Frequently Asked Questions (FAQ)

Q1: Kya hum bina strcpy() ke string copy kar sakte hain?
A: Haan, hum for loop ka use karke character-by-character manually copy kar sakte hain.

Q2: strcpy() aur strncpy() mein kya farq hai?
A: strncpy() zyada safe hai kyunki ismein hum limit set kar sakte hain ki kitne characters copy karne hain.

Disclaimer: Yeh program educational purposes ke liye hai. Alag-alag compilers (jaise Turbo C++ vs VS Code) mein minor changes ho sakte hain. Koshish karein ki modern compilers ka use karein.