The __set__get__unset__isset of the PHP magic method

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2. <?php
4. /***
6. Magic Method:
8. Refers to methods that are automatically called in some cases, called magic methods
10. PHP Object-oriented, which provides a few magic methods,
12. They are characterized by a double underline __
14. __construct (), __destruct (), __call (), __callstatic (), __get (), __set (), __isset (), __unset (), __sleep (), __wakeup (), __ ToString (), __invoke (), __set_state () and __clone ()
16. __construct: Construction method
18. __destruct: The destructor method
20. __clone (): Clone method that will automatically be called when the object is cloned
22. ***/
24. __clone (): Clone method that will automatically be called when the object is cloned
26. Class Human {
28. public $age = 22;
30. Public function __clone () {
32. Echo ' Someone cloned me! '
34. }
36. }
38. $lisi = new Human ();
40. $zhangsan = Clone $lisi;
42. /*
44. Results:
46. Someone cloned me! fake
48. */
52. ?>

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2. <?php
6. Magic Method __get
8. Class Human {
10. private $money = ' 302 ';
12. protected $age = 23;
14. public $name = ' Lily ';
16. Public function __get ($p) {
18. echo ' You want to visit my ',$p,' attribute <br/> ';
20. }
22. }
24. $lily = new Human ();
26. Echo $lily->name; Lily
28. echo $lily->age; //You want to access my age property
30. echo $lily->money; //You want to access my Money property
32. echo $lily->friend; //You want to access my friend Properties
34. /*
36. Can be summed up:
38. When we invoke a property that is not allowed to call on a permission, and a property that does not exist,
40. __get Magic method will be called automatically,
42. and automatically, the parameter value is the attribute name.
44. Process:
46. $lily->age--is not entitled to-->__get (age);
48. $lily->friend--does not have this attribute-->__get (' friend ');
50. In life, you help people guard the shop.
52. Buy Toothbrush---> Good, give you a toothbrush
54. Buy Towels---> Good, give you a towel
56. This POS machine is very good---> (pos is the tool of the store, private, not sold: "You do not have the right to buy"), but we use the __get method,
58. There is a friendly opportunity to deal with it.
60. The system will directly error, even fatal error, through __get, we can customize user access, the processing behavior.
62. */
64. echo ' <br/> ';
68. Set properties that are not
70. $lily->aaa = 111;
72. $lily->bbb = 222;
74. Print_r ($lily);
78. /*
80. Results
82. Human Object
84. (
86. [Money:Human:private] = 302
88. [age:protected] = 23
90. [Name] = Lily
92. [AAA] = 111//Added properties
94. [BBB] = 222//Added properties
96. )
100. */
104. /*
106. Even added it.
108. In fact, the object is a set of properties, in JS more obvious.
110. If you can add attributes so casually, this object has too many attributes and is not manageable.
112. */
116. ?>

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2. <p><?php
4. Magic Method __set
6. Class Stu {
8. private $money = ' 302 ';
10. protected $age = 23;
12. public $name = ' Hmm ';
14. Public function __set ($a,$b) {
16. echo ' You want to set my ',$a,' attributes ',' <br/> ';
18. echo ' and value is ',$b,' <br/> ';
20. }
22. }
24. echo '
26. $HMM = new Stu ();
28. $HMM->aaa = 111; //You want to set my AAA property and the value is 111
30. $HMM->money = ' 402 '; You want to set my Money property and the value is 402
32. $HMM->age = ' 28 '; //You want to set my age property and the value is
34. Print_r ($hmm);
36. /*
38. Results
40. Stu Object
42. (
44. [Money:Stu:private] = 302
46. [age:protected] = 23
48. [Name] + Hmm
50. )
52. */
54. $HMM->name = ' hanmm ';
56. Print_r ($hmm);
58. /*
60. Results
62. Stu Object
64. (
66. [Money:Stu:private] = 302
68. [age:protected] = 23
70. [Name] = HANMM
72. ) </p><p>*/
74. /*
76. As above, summed up the role of __set
78. When you assign a value to a property that is not authorized to operate,
80. Or a non-existent attribute is assigned a value,
82. __set () Automatic call
84. and automatically passes 2 parameter attribute property values
86. Cases:
88. $HMM->age =---not entitled to---> __set (' Age ', 28);
90. */</p><p>?></p>

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2. <?php
4. Magic Method __isset __unset
6. echo '
8. Class Dog {
10. public $leg = 4;
12. protected $bone = ' pig leg bone ';
14. Public function __isset ($p) {
16. echo ' You want to judge me ',$p,' attribute exists <br/> ';
18. return 1;
20. }
22. Public function __unset ($p) {
24. echo ' you want to get rid of my ',$p,'?!   <br/> ';
26. }
28. }
30. $hua = new Dog ();
32. if (Isset ($hua->leg)) {
34. echo $hua->leg,' <br/> ';
36. }
38. /*
40. Results: 4
42. */
44. if (Isset ($hua->tail)) {
46. echo ' has tail attribute ';
48. } Else {
50. echo ' no tail ';
52. }
54. /*
56. Results:
58. You want to tell me that my tail property doesn't exist.
60. Has tail property
62. */
66. /***
68. __isset () method,
70. When using Isset () to determine an object that is not visible (protected/private/a property that does not exist)
72. Will cause __isset () to execute
74. Q: Isset ($obj->xyz) property, True,
76. Can you explain that the class declares an XYZ property?
78. Answer: No
80. ***/
82. echo '
84. echo ' __unset test <br/> ';
86. Print_r ($hua);
88. /*
90. Results:
92. __unset Test
94. Dog Object
96. (
98. [Leg] = 4
100. [bone:protected] = pork leg Bone
102. )
106. */
108. unset ($hua->leg);
110. Print_r ($hua);
112. /*
114. Results:
116. Dog Object
118. (
120. [bone:protected] = pork leg Bone
122. )
124. */
126. unset ($hua->tail);
128. unset ($hua->bone);
130. /*
132. Results:
134. You want to get rid of my tail?!.
136. You want to get rid of my bone?!.
138. */
140. /***
142. __unset () method
144. When you destroy an object's invisible property with unset,
146. Will trigger __unset ();
148. unset ($hua->tail)----No tail attribute---->__unset (' tail ');
150. ***/
152. ?>

The __set__get__unset__isset of the PHP magic method