PHP website development variable scope _ PHP Tutorial

PHP website development variable scope. 1. there is no global static variable in php. In previous. Net development, some data can be cached using the following method: viewplaincopytoclipboardprint? PublicclassTest {priva

1. there is no global static variable in php.

In previous. Net development, you can use the following method to cache some data:

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Public class Test {
Private static int Count = 0; // This variable is valid throughout the application.
}

Public class Test {
Private static int Count = 0; // This variable is valid throughout the application.
}

Php is an interpreted language. although there is a static modifier, the meaning is completely different from that in. Net.
Even if you declare a variable in the class as static, this variable is only valid in the current page-level application domain.

2. understand the scope of variables.

Variables declared in vitro of the method cannot be accessed in the method body.
For example:

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$ Url = "www.webjx.com ";
Function _ DisplayUrl (){
Echo $ url;
}
Function DisplayUrl (){
Global $ url;
Echo $ url;
}
_ DisplayUrl ();
DisplayUrl ();
?>

$ Url = "www.webjx.com ";
Function _ DisplayUrl (){
Echo $ url;
}
Function DisplayUrl (){
Global $ url;
Echo $ url;
}
_ DisplayUrl ();
DisplayUrl ();
?>

The _ DisplayUrl method does not display any results, because the variable $ url cannot be accessed in the method body _ DisplayUrl. you can add global before $ url, such as the DisplayUrl method.

Global variables defined in the method body can be accessed in the method body in vitro:

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Function _ DisplayUrl (){
Global $ myName;
$ MyName = yibin;
}

_ DisplayUrl ();
Echo $ myName; // output yibin
?>

Bytes. In previous. Net development, some data can be cached using the following method: view plaincopy to clipboardprint? Public class Test {priva...