Can use <, >, ==, !=, ||, &&, also % for modulo(ie divide 1st number by 2nd and return remainder). Note use of double equals for an equality check (remember = is used to assign variables).
Can also be used with booleans
As an alternative to if/else use switch/case.
Important to use break to otherwise all options below the chosen case are selected.
A less well known operator but with many uses is the ternary operator that uses a question mark (?) and colon (:) in combination. A ternary or three-value logic statement is constructed as follows:
(1) ? (2) : (3)
If ‘1’ is true then ‘2’ is returned. If (1) is false then (3) is returned.
This is a useful way of checking for the presence of variables and assigning default values if they are missing.
$theValue = (!get_magic_quotes_gpc()) ? addslashes($theValue) : $theValue;
The above ternary example checks to see if magic quotes are on and if not then applies the addslashes() function.