PHP
Reference
Newbie Traps & Pitfalls
PHP will let you get away with a lot of syntax mistakes which are perfectly valid code (often creating unexpected variables in the process) but not what you intended. Most of the following produced no immediate error messages; the code simply wouldn't work, and it took me several edit-upload-run cycles to find each problem. Here are some mistakes I made when re-learning PHP in 2005 after not using it since 1997:
- Classes
- Member vars and functions must always be referred to using $this->FunctionName()
- However, var members do not take a $ prefix: $this->varName
- If you pass an object to a function, the function will be operating on a copy of the object unless the function is called with the object passed as a reference: CalledFunction(&$objName);. The function declaration itself needs no modifications.
- If the function is expected to store the object for later use (e.g. it is a class constructor), the function must also use a reference when saving the object: $this->localName =& $iObjectParam;. Otherwise (again) it will be using a copy, not the original.
- Operators
- The "is equal to" comparison operator is "==" (as in c/c++), not "="