sprintf of error summarization in C + + _c language

sprintf is a variable parameter function that often goes wrong when used, and as long as the problem is usually a memory access error that can cause the program to crash.
The following is a simple summary of the error problems that sprintf frequently make:

1, buffer overflow:The length of the first argument is too short to solve: extend the length of the first argument. When printing a string, try to specify the maximum number of characters using the form "%.NS"
Char buf[5];
sprintf (BUF, ":%d", 3246);
printf ("Buf is%s\n", buf);

Modify BUF to Char Buf[6]

2, forget the first parameter: reason with printf used to use the habit, occasionally forget
Char buf[6];
sprintf (":%d", 3246);
printf ("Buf is%s\n", buf);

Error C2664: ' sprintf ': cannot convert parameter 2 from ' int ' to ' const char * '

3, variable parameters corresponding to the problem:Usually forget to provide a corresponding format of the variable parameter, resulting in all the wrong parameters, check and check it. Especially those parameters that correspond to the "*", are they provided?
Do not match an integer to a "%s"

Char buf[100];
int a=6;
sprintf (buf, ":%d,%s", 3246,a);
printf ("Buf is%s\n", buf);

Warm tip: A corresponds to%d instead of%s

4, there are the following such a mistake, I can only sense do not know how to describe. Now give an example of the wrong code and the correct code. Let's see for yourselves.
The wrong code
Char buf[15];
Char a1[] = {' A ', ' B ', ' C ', ' D ', ' E ', ' F ', ' G '};
Char a2[] = {' H ', ' I ', ' J ', ' K ', ' L ', ' M ', ' N '};
sprintf (buf, "%s%s", a1, A2); Garbled, the result is not what we need
printf ("Buf is%s\n", buf);

the right code
Char buf[15];
Char a1[] = {' A ', ' B ', ' C ', ' D ', ' E ', ' F ', ' G '};
Char a2[] = {' H ', ' I ', ' J ', ' K ', ' L ', ' M ', ' N '};
sprintf (buf, "%.7s%.7s", a1, A2);//produce: "ABCDEFGHIJKLMN"
printf ("Buf is%s\n", buf);