Fourth Chapter _php Basic Grammar (2) _php tutorial

1. Declaration of constants

In PHP, define constants using the Define () function to implement

2. Magic Constants

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	Returns the current line number in the file
__file__	Returns the full path and filename of the file
__dir__	Returns the directory where the file resides
__function__	Returns the name of the function when it is defined
__class__	Returns the name of the class when it is defined
__mthod__	Returns the name of the method to which the class was defined

The test code is as follows:

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  < span="">     < span="">< span="">< span="">         < span="">'
The name of this function is: '. < span="">< span="">< span="">< span="">< span=""><   c27>< span="">  '
This is the first '. < span="">.' Yes. '< span="">< span="">< span=""> '
The absolute path to this file is: '. < span="">< span="">< span="">< span="">< span=""> ? >

3. Reference Assignment

Access the same variable content with a different variable name, and the other changes as the value of one of the variables changes.

4. Logical operators

With && or | |　　Non -! XOR

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  < span="">     < span="">=< span="">< span="">< span="">< span="">=< span=""> < span="">< span="">< span="">< span="">(< span=""> < span="">); < span=""> '
'< span="">< span="">< span="">(< span="">< span="">); < span=""> '
'< span="">< span="">< span="">(< span="">< span="">); < span=""> '
'< span="">< span="">< span="">(! < span="">); < span=""> '
 < span="">  '  ?>< span=""> 

5. Comparison operators

① equals = = $a = = $b when a value of $ A equals the value of $b, returns True, otherwise false

② congruent = = = $a = = = $b when a value of $ A equals the value of $b, and $ A is equal to the type of $b, returns True, otherwise false

③ Range! = or <>

④ not congruent! ==

　　6. Bitwise operators

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Bitwise-AND	&	is 1 position 1, the rest is 0
Bitwise OR	|	There is a position of 1 for 1 and the rest to 0
Bitwise XOR OR	^	Different positions are 1 and the rest is 0
Bitwise non-	~	1 of the position is 0,0 position is 1
Move left	<<	BITS move n times to the left, which is equal to 2 times each move
Move right	>>	BITS move n times to the right, which is equivalent to dividing by 2 per move

 
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 < span="">  "  < span=""> $a |< span="">   $b = '. (< span=""> | < span="">).'
 < span="">  "  < span=""> $a ^ $b = '.< span="">   (< span=""> ^ < span="">).'
 < span="">  "  < span=""> ~ $a = '.< span="">   (~< span="">).'
 < span="">    "< span=""> $a <<4=  ." < span=""> (< span=""><<4). '
 < span="">    "< span=""> $b >>4=  ." < span=""> (< span="">>>4). '
 < span="">  '  ?>< span=""> 

7. String operators

(.) and (. =) and {}

8. Array operators (omitted)

9. Type operator

Type operators are commonly used by instanceof to determine whether a variable belongs to an instance of a class.

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  < span="">     < span="">< span="">< span="">         < span="">< span="">< span="">< span="">< span="">< span="">< span="">< span="">< span="">< span="">< span="">=< span="">< span="">< span="">< span="">((< span=""> instanceof A)); < span=""> '
< span="">'< span="">  ((  instanceof B));< span="">< span=""> < span=""> '
 < span="">  '  ?>< span=""> 

10. Error control operator @

http://www.bkjia.com/PHPjc/626587.html www.bkjia.com true http://www.bkjia.com/PHPjc/626587.html techarticle 1. Declaration of constants in PHP, define constants using the Define () function to implement 2. Magic constant Returns the current line number in the file __file__ returns the full path and file name of the file __dir ...

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