Example analysis of namespace use usage in php

The example in this article describes the usage of namespace use in php. I share it with you for your reference, the details are as follows:

Now it feels a bit outdated to say this, but I feel that not many people use namespace, probably because they are not used to it.

Class organizes functions one by one, and namespace can be understood as organizing classes, functions, etc. in an orderly manner. Personally, I think the main advantages of namespace are

First, it can better manage the code
Second, with more files, duplicate names of classes and functions can be avoided
Third, code readability is enhanced

1. Definition namespace

namespace userCenter;
//php代码
namespace userCenter\register;
//php代码
namespace userCenter\login {
 //php代码
}

Namespace cannot be nested or declared multiple times in the same code (only the last one will be recognized). However, you can define multiple namespaced codes in the same file. It is more appropriate to define a namespace for each file (it can be the same namespace).

2. Call namespace

\userCenter\register; //绝对调用
userCenter\login; //相对调用
use userCenter\register; //引用空间
use userCenter\register as reg; //引用空间并加别名

3. Example description

login.class.php

<&#63;php
namespace userCenter;
function check_username(){
 echo "login OK<br>";
}
class login{
 public function save(){
 echo "login had saved<br>";
 }
}
?>

regist.class.php

<?php
namespace userCenter\regist
{
 function check_username() {
 echo "regist OK<br>";
 }
 class regist{
 public function save(){
 echo "regist had saved<br>";
 }
 }
}
?>

test.php

<&#63;php
require "login.class.php";
require "regist.class.php";
use userCenter\regist; //使用use调用空间
use userCenter\regist as reg; //as定义别名
echo \userCenter\check_username(); //绝对调用
$login = new \userCenter\login();
echo $login->save();
echo regist\check_username(); //相对调用
echo reg\check_username(); //别名调用
$regist = new reg\regist();
echo $regist->save();

Use use, than Absolutely The call should be better, such as adding a prefix to class, function, etc., so that it looks clearer.

I hope this article will be helpful to everyone in PHP programming.

The above introduces the analysis of namespace use usage in PHP, including the content. I hope it will be helpful to friends who are interested in PHP tutorials.