write a function for copying two strings-CodePudding

this code is not printing the copied value of two strings given that are target and source been created above then a function is created that is stringcopy .

#include <stdio.h>

int stringcopy(char *target, char *source) {
    char *start = target;

    while (*target != '\0') { // this means while target is not equal to 0 that is null charecter
        *target = *source;
        target  ;
        source  ;
    }

    *target ='\0';
    return *start;
}

int main() {
    char source[34] = "Harry";
    char target[34];

    char copy = stringcopy(target, source);
    printf("%s", copy);

    return 0;
}

CodePudding user response：

*target != '\0' but *target is uninitialized. You mean *source != '\0'`.

Next problem: int stringcopy should be char *stringcopy. Your code will appear to work on a 32 bit platform otherwise, but it will blow up x64. You need to return the correct type.

Third problem: char copy = ; should be char *copy = ; I'm guessing you got here by arbitrarily mutating the code to get it to compile due to the second problem.

Forth problem: return *start; should be return start;. Thanks to Gerhardh for catching it.

CodePudding user response：

It wasn't me, but someone has written such a function, years ago: strdup

CodePudding user response：

Please see the comments below

#include <stdio.h>

void stringcopy(char *target, char *source) { // nothing need to be returned
    // What is the point of this ? char *start = target;

    while (*target != '\0') { // this means while target is not equal to 0 that is null charecter
        *target = *source;
        target  ;
        source  ;
    }

    *target ='\0';
    return; // start not required?  Could even delete this line
}

int main() {
    char source[34] = "Harry";
    char target[34];

    stringcopy(target, source); // Do not need to return anything
    printf("%s", target); // No need for copy

    return 0;
}