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SUMMARY
The text below lists some of the most common errors that occur programming in the C language. Any one of these items can cause unpredictable results, such as invalid data.
- Using an automatic variable that has not been initialized
- Omitting a closing comment delimiter
- Using an array index greater than the length of the array (In C, array indexes run from zero to <length>-1.)
- Omitting a semicolon or a closing brace
- Using an uninitialized pointer
- Using a forward slash when a backslash is required (for example, substituting "/n" for "\n.")
- Using "=" in a comparison where "==" is desired
- Overwriting the null terminator for a string
- Prematurely terminating a function declaration with a semicolon (The compiler often flags the "orphan" block of code as a syntax error.)
- Specifying the values of variables in a scanf() statement instead of their addresses
- Failing to declare the return type for a function
- Assuming an expression evaluation order when using an expression with side effects (For example, a[i] = i++; is ambiguous and dangerous.)
- Failing to account that a static variable in a function is initialized only once
- Omitting a "break" from a case in a switch statement (Execution "falls through" to subsequent cases.)
- Using "break" to exit a block of code associated with an if statement (The break statement exits a block of code associated with a for, switch, or while
- statement.)
- Comparing a "char" variable against EOF (-1). The following idiom results in an infinite loop:
char c;
while ((c = getchar()) != EOF)
{
}
Copyright (c) 1999 - 2001, robert han, all rigths are reserved.