C strcpy() Function

Posted in C Tutorial

Updated on Jan 14, 2024

By Mari Selvan

👁️ 207 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In C programming, manipulating strings is a common and essential task.

The strcpy() function is a standard library function that is used to copy one string to another.

In this tutorial, we'll explore the usage and functionality of the strcpy() function.

💡 Syntax

The signature of the strcpy() function is as follows:

Syntax

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

This function copies the string pointed to by source (including the null terminator \0) to the array pointed to by destination. The function returns the destination string.

📄 Example

Let's delve into an example to illustrate how the strcpy() function works.

strcpy.c

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

int main() {
  char source[] = "Hello, World!";
  char destination[20];

  // Copy the string from source to destination
  strcpy(destination, source);

  // Output the result
  printf("Source: %s\n", source);
  printf("Destination: %s\n", destination);

  return 0;
}

💻 Output

Output

Source: Hello, World!
Destination: Hello, World!

🧠 How the Program Works

In this example, the strcpy() function copies the string "Hello, World!" from the source array to the destination array.

↩️ Return Value

The strcpy() function returns a pointer to the destination string. It is good practice to use the destination string directly rather than relying on the return value.

📚 Common Use Cases

The strcpy() function is commonly used when you need to duplicate a string, creating a copy that can be modified independently of the original. It's essential for tasks such as string manipulation and dynamic memory allocation.

📝 Notes

Ensure that the destination array has enough space to accommodate the source string along with its null terminator. Failure to allocate enough space can lead to buffer overflow issues.
If the destination and source strings overlap, the behavior is undefined. To copy overlapping strings, consider using memmove().

🎢 Optimization

The strcpy() function is optimized for simplicity and general use. If you are working with known string sizes, consider using safer alternatives like strncpy() to prevent buffer overflows.

🎉 Conclusion

The strcpy() function in C is a fundamental tool for string manipulation. It provides a straightforward way to copy strings, facilitating tasks such as string concatenation, substring extraction, and more.

Feel free to experiment with different strings and explore the behavior of the strcpy() function in various scenarios. Remember to handle string lengths and null terminators appropriately for robust string copying. Happy coding!