ID Number: Q22321
3.00 4.00 5.00 5.10 6.00 6.00a 6.00ax 7.00 | 5.10 6.00 6.00a
MS-DOS | OS/2
Summary:
The following is a list of the most common C programming errors.
More Information:
Any of these items could cause unpredictable results, such as trashed
data or a system hang.
1. Using auto variables that have not been initialized.
2. Leaving out the closing comment delimiter.
3. Over-indexing an array.
4. Leaving out a semicolon (;) or brace ({}).
5. Using uninitialized pointers.
6. Using break with an IF block. (Break does not exit out of IF blocks.
It only breaks you out of WHILE, FOR, or SWITCH loops.)
7. Comparing a char variable against EOF, as in the following example:
char c;
while ((c=getchar()) != EOF)
{
}
If c is a char, you cannot test c against EOF because a -1 cannot
fit into a character, so c must be an int.
8. Using a forward slash instead of a backslash (for example, /n
instead of \n).
9. Using = instead of == in a comparison.
10. Overwriting the null terminator (the last byte) in a string by
indexing 1 byte too far.
11. Placing a semicolon improperly, as in the following example:
void function(int a,char b); /* semicolon does not belong here */
{ }
12. Forgetting that scanf() expects addresses.
13. Using the wrong return value for a function. For example, a
function that returns a real, but is not declared, will return an
int by default.
14. Using expressions with side effects. For example, a[i] = i++; is
ambiguous.
15. Forgetting that static variables inside functions are initialized
only once.
16. Unintentionally omitting a break from a case label in a switch
statement, and therefore falling through to the next case.
Additional reference words: 5.00 5.10 6.00 6.00a 6.00ax 7.00