strcpy in C++

strcpy() is a standard library function in C++ and is used to copy one string to another. In C++ it is present in the <string.h> and <cstring> header files. 

Syntax:

char* strcpy(char* dest, const char* src);

Parameters: This method accepts the following parameters:  

• dest: Pointer to the destination array where the content is to be copied.
• src: string which will be copied.

Return Value: After copying the source string to the destination string, the strcpy() function returns a pointer to the destination string.

Example:

C++

// C++ program to illustrate
// strcpy() function in C/C++
#include <iostream>
#include <cstring>
using namespace std;

int main()
{
    // Strings Declared
    char str1[] = "Hello Geeks!";
    char str2[] = "GeeksforGeeks";

    char str3[40];
    char str4[40];

    char str5[] = "GfG";

    // String copy used
    strcpy(str2, str1);
    strcpy(str3, "Copy successful");
    strcpy(str4, str5);

    // Strings Printed
    cout << "str1: " << str1 << "\nstr2: " << str2
         << "\nstr3: " << str3 << "\nstr4: " << str4;

    return 0;
}

Output

str1: Hello Geeks!
str2: Hello Geeks!
str3: Copy successful
str4: GfG

Time Complexity: O(n)
Auxiliary Space: O(1)

Important Points:

• This function copies the entire string to the destination string. It doesn’t append the source string to the destination string. In other words, we can say that it replaces the content of the destination string with the content of the source string.
• It does not affect the source string. The source string remains the same after copying.
• This function only works with C style strings and not C++ style strings i.e. it only works with strings of type char str[]; and not string s1; which are created using standard string data type available in C++ and not C.