The functions of operators are divided into:
1. Operation operator + - * / % ++ --
Second, character operators. //Connection operator
3. Assignment operator = += -= *= /= %= .=
Fourth, the comparison operator> < >= <= == === != or <> !==
5. Logical operators && or and || or or ! or not
6. Bitwise operators & | ^ ~ << >> >>>
7. Other operators ?: '' @ => -> :: & $
Precautions:
1.% has two purposes: integer division operation; control range, do not use decimals, and do not use negative numbers
2.% will convert the numbers on both sides to integers and then divide them more closely
3.++ -- Usage
$a=10; $b= $a++; //b=10,a=11; $c = --$b;//c=9,b=9 // 9 + 11 $d=$c++ + ++$c;//d=20,c=11 // 20 - 18 $ e = $ d-- - - $ d; // e = 2 echo $e;
4. === Not only requires the same content, but also the same type when comparing
5. Short circuit problem: && and || will short circuit
&& is doing the operation, if the previous number is false, then whether the latter is true, the regular expression is false, and the latter expression will not be executed
|| In the operation, if the previous number is true, then whether the latter is false, the regular expression is true, and the latter expression will not be executed.
& and | do not short-circuit