Concatenation ?

my objective is to strcat(src1, src2) and save it to the variable result.



My attempt:


result = strcat(src1, src2);


But some people are saying my theory is wrong. Can someone show me how to save my result from strcat(src1, src2) to the variable result please ?

Your theory is wrong. strcat() always returns the dest pointer anyway, so capturing it is usually pointless. Read the man page, carefully:

Code:

---

SYNOPSIS
      #include <string.h>

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

      char *strncat(char *dest, const char *src, size_t n);

DESCRIPTION
      The  strcat()  function appends the src string to the dest
      string overwriting the `\0' character at the end of  dest,
      and  then  adds a terminating `\0' character.  The strings
      may not overlap, and the  dest  string  must  have  enough
      space for the result.

      The  strncat()  function  is similar, except that only the
      first n characters of src are appended to dest.

RETURN VALUE
      The strcat() and strncat() functions return a  pointer  to
      the resulting string dest.

---

Sorry for being a noob. My second attempt. Please help if u see something wrong:

src1 = strcat(src1, src2)

result = strcpy(src1) // result = src1 + src2 ?

Would that work?

strcat(param1 , param2);

strcat will allways concat param2 to param1 ! Depending on what you are trying to do you can also use sprintf.

Code:

---

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

main() {
        char src1[]="Hello ";
        char src2[]="World !";
        char buff1[BUFSIZ];

        printf("src1: [%s]\n",src1);
        printf("src2: [%s]\n",src2);
        sprintf(buff1,"%s%s",src1,src2);
        printf("buff1: [%s]\n",buff1);
        strcat(src1, src2);
        printf("src1: [%s]\n",src1);
        printf("src2: [%s]\n",src2);
}

---

Output:
src1: [Hello ]
src2: [World !]
buff1: [Hello World !]
src1: [Hello World !]
src2: [World !]

Hope it helped !

Quote:

---

result = strcpy(src1) // result = src1 + src2 ?

---

You should use strcpy() like this:

strcpy (result, src1);

The function returns result.

src1 = strcat(src1, src2)

result = strcpy(result, src1)


Thank you guys :)

BTW, here's a useful online reference.
http://www.cppreference.com/

Quote:

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Originally Posted by koolguysj

src1 = strcat(src1, src2)

result = strcpy(result, src1)

---

Theres no need to capture the result of strcat or strcpy, in this situation.

this should suffice if you really want to use an extra variable:

Code:

---

...
strcpy(result,src1);
strcat(result,src2);
...

---

No need to assign the result of strcpy or strcat to anything.

Quote:

---

Originally Posted by groorj

strcat(param1 , param2);

Code:

---

...
        char src1[]="Hello ";
        char src2[]="World !";
...
        strcat(src1, src2);
...
        return 0;
}

---

---

This is will most likely cause a seg fault. You're writing past the end of your array.