Php & logic and operator usage-PHP source code

If the previous result is false, the operation is not executed. if the result is true, continue with the following operations. If the previous result is false, the operation is not executed. if the result is true, continue with the following operations.

Example:
! Defined ('Magic _ QUOTES_GPC ') & define ('Magic _ QUOTES_GPC', get_magic_quotes_gpc ());

O (zookeeper) o Alas, I was dizzy. today I asked N more people. Finally, I figured out what was going on "&".

The operator does not determine what it means. well, if the previous operator is false. The subsequent statements are not executed. So that we do not have to write if

This is simple...

// Simple description: if the previous judgment is false, the operation is not executed. if the judgment is true, the following definition constant operation is continued.

Logical operators

Example	Name	Result
$ A and $ B	And (logical And)	TRUEIf both $ a and $ B areTRUE.
$ A or $ B	Or (logical Or)	TRUEIf either $ a or $ B isTRUE.
$ A xor $ B	Xor (logical exclusive or)	TRUEIf either $ a or $ B isTRUEBut not at the same time.
! $	Not (logical non)	TRUEIf $ a is notTRUE.
$ A & $ B	And (logical And)	TRUEIf both $ a and $ B areTRUE.
$ A | $ B	Or (logical Or)	TRUEIf either $ a or $ B isTRUE.

Example #1 Example of logical operators

The code is as follows:

The output in the above example is similar:
Bool (true)
Bool (false)
Bool (false)
Bool (true)

Another example that might help.

(Isset ($ panelemail )&&! Empty ($ panelemail )? $ Panelemail: $ userdata ['email ']);
?>
Returns the userdata email address, but this

(Isset ($ panelemail) AND! Empty ($ panelemail )? $ Panelemail: $ userdata ['email ']);
?>
Returns false.

The reason is that the two types of ands have a different order of precedence. "&" is higher than "AND", and "? : "Operator just happens to come between the two. also, since "|" (or) is actually higher than "AND," you shoshould never mix & s and | s with ANDs and ORs without paretheses.

For example:

True & false | false
?>
Returns false,

True AND false | false
?>
Returns true.