10 article recommendations on global variables

Source: Internet
Author: User
What is a global variable? A global variable, also known as an external variable, is defined outside the function and is scoped to the end of the program file, starting at the definition of the variable. Unlike other programming languages, global variables are not automatically set to be available. In the previous section we introduced the local variables of the scope of the PHP variable, in PHP, because the function can be treated as a separate program snippet, so the local variable overrides the visibility of the global variable, so the global variable cannot be called directly in the function. The format of its code is as follows: <?php $one = 10; $two = 20; The test cannot use the global variable directly inside the function $one and $two function sum () {//A new declaration within the function and no two variables assigned the initial value 1. What is a global variable? The PHP variable's fan

1.10 articles about the range of variables recommended

Summary: What are global variables? A global variable, also known as an external variable, is defined outside the function and is scoped to the end of the program file, starting at the definition of the variable. Unlike other programming languages, global variables are not automatically set to be available. In the previous section we introduced the local variables of the scope of the PHP variable, in PHP, because the function can be treated as a separate program snippet, so the local variable overrides the visibility of the global variable, so the global variable cannot be called directly in the function. The format of its code is as follows: &lt;? php&nbsp; $one ...

2.7 article recommendations on static global variables for PHP

Summary: Local variables can be classified as dynamic storage type and static storage type from storage mode. Local variables in a function, such as not specifically declared as static storage classes, are dynamically allocated storage space by default. The internal dynamic variables are automatically freed after the function call ends. If you want the internal variables to remain in memory after the function executes, you should use a static variable. After the function has been executed, the static variable does not disappear, but it is shared among all calls to the function, that is, when the function executes again, the static variable will continue the previous result, and only in the execution period of the script ...

3. A detailed introduction to PHP variables

Summary: What are global variables? A global variable, also known as an external variable, is defined outside the function and is scoped to the end of the program file, starting at the definition of the variable. Unlike other programming languages, global variables are not automatically set to be available. In the previous section we introduced the local variables of the scope of the PHP variable, in PHP, because the function can be treated as a separate program snippet, so the local variable overrides the visibility of the global variable, so the global variable cannot be called directly in the function. The format of its code is as follows: &lt;? php&nbsp; $one ...

4. How to realize the Modularization of JS code

Summary: Because variables and functions declared in the global scope automatically become properties of the Global Object window, which often results in naming conflicts, the more global variables, the greater the probability of introducing bug bugs! So we should use as few global variables as possible ..., HTML5 China, China's largest HTML5 chinese portal.

5. Differences between global and hyper-global variables in PHP

Introduction: This article mainly introduces the PHP global variable and the Super global variable difference, a more detailed analysis of the PHP global variables and Super global variables concept, usage and use differences, the need for friends can refer to the next

6. How to use global variables in PHP

Introduction: This article is on the use of global variables in PHP a few ways to analyze the detailed introduction, the need for a friend reference

7. Differences between local variables and global variables in PHP functions

Summary: Variables defined within a program are called local variables and are used only within the program and disappear with the program ending. Variables that are defined outside the program are called global variables and can be paged by the program, but will not disappear with the end of the program.

8. Explanation of the difference between static and static local variables

Summary: Local variables can be classified as dynamic storage type and static storage type from storage mode. Local variables in a function, such as not specifically declared as static storage classes, are dynamically allocated storage space by default.

9. What are global variables? Examples of global variables for the range of PHP variables

Summary: A global variable, also known as an external variable, is defined outside the function and is scoped to the end of the program file, starting at the definition of the variable.

10. In-depth analysis of pre-parsing and side-effects in Javascriptvar

Summary: The side effects of var implicit global variables and well-defined global variables have a small difference between the ability to make a variable undefined by using the delete operator. Global variables created by VAR (created in programs other than functions) cannot be deleted. Implicit global variables created without VAR (regardless of whether they were created in a function) can be deleted. This shows that, technically, implicit global variables are not real global changes.

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