How to create a horizontal colon in vertical text in PS

The scope of variables in PHP

What is the scope of variables?

Variable scope refers to the part of the program where the variable can be accessed.

Variable scope in PHP

There are three variable scopes in PHP:

1. Local scope

Local variables are only visible within the function in which they are declared. If you declare a variable within a function, the variable is not available outside that function.

2. Function parameter scope

Function parameters are visible inside the function, but not visible outside the function.

3. Global scope

Global variables can be accessed from any part of the program. Global variables need to be declared using the global keyword.

Factors affecting variable scope

• Location of variable declaration
• global Use of keywords
• Function call

Example

<code class="php">// 局部作用域
function myFunction() {
    $local = "This is a local variable";
}

// 函数参数作用域
function myFunction2($param) {
    echo $param;
}

// 全局作用域
$global = "This is a global variable";</code>

In the example:

• $local Only available within the myFunction() function.
• $param Available only within the myFunction2() function.
• $global can be used in any part of the program.

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