Here are some common programming errors made in C. Please add on…
1) Not initializing pointers
Anytime you use a pointer, you should be able to answer the question: What variable does this point to? If you cannot answer this question, it is likely it doesn’t point to any variable.
This type of error will often result in a Segmentation fault/coredump error on UNIX/Linux or a general protection fault under Windows.
char * st; /* defines a pointer to a char or char array */
strcpy(st, “abc”); /* what char array does st point to?? */
2) String Errors
Confusing character and string constants
char ch = ‘A’; /* correct */
char ch = “A”; /* error */
3) Comparing strings with ==
Never use the == operator to compare the value of strings! Strings are char arrays. The name of a char array acts like a pointer to the string
4) Not null terminating strings
C assumes that a string is a character array with a terminating null character. This null character has ASCII value 0 and can be represented as just 0 or ‘\0’. This value is used to mark the end of meaningful data in the string. If this value is missing, many C string functions will keep processing data past the end of the meaningful data and often past the end of the character array itself until it happens to find a zero byte in memory.
5) Not leaving room for the null terminator
A C string must have a null terminator at the end of the meaningful data in the string. A common mistake is to not allocate room for this extra character. For example, the string defined below
char str[30];
only has room for only 29 (not 30) actually data characters, since a null must appear after the last data character.
Refer the following link for more:
www.andromeda.com/people/ddyer/topten.html
