New global variable syntax in PHP8.0

Recently, PHP8.0 was officially released, and the new version brings many exciting new features. One of the new features that has attracted much attention is the update to the global variable syntax. In older versions of PHP, we introduced a global variable into the current scope by using the global keyword inside a function. In PHP8.0, this method will no longer be recommended, replaced by a new global variable syntax.

Traditional use of global variables:

In older versions of PHP, we can use the global keyword to introduce a global variable:

$x = 1;
function test(){
    global $x;
    echo $x;
}

test();  //输出 1

In the above code , we use the global keyword in function test to introduce $x into the function. In PHP8.0, this method is still available, but it is no longer officially recommended.

New way to use global variables:

In PHP8.0, we can define a global variable by adding the global keyword before the variable name. For example, the following code demonstrates how to define a global variable:

global $x = 1;
function test(){
    echo $x;
}

test();  //输出 1

In the above code, we add the global keyword while defining $x. In this way, $x becomes a global variable and can also be accessed within the test function.

It is worth noting that the new global variable syntax can only be used when the variable is defined and cannot be used inside the function. For example, the following method is incorrect:

function test(){
    global $x = 1;  //Syntax error
    echo $x;
}

Summary:

The new global variable syntax in PHP8.0 brings us a more convenient and intuitive way to define global variables . Although the change in this feature is not huge, it reflects the development direction of the PHP language, which is to pay more attention to the intuitiveness and ease of use of the language.

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