Use keyword in various aspects of life in PHP

The use keyword is not only involved in the oriented process of PHP, It also steals the show in PHP object-oriented. In the actual development process, it is also spread throughout the source code. This article will make a summary of the use keyword.

1. Reference for namespace

<?php
namespace admin\controller;
use \core\controller; //引入命名空间
class ArticleController extends Controller{
    public function index(){

  }
}
?>

2. Keyword for alias

namespace space;
function display(){}
class Man{}
const PI = 3.14;
 
namespace space1;
class Man{}
//引入空间元素
//use space\Man;                //错误：当前空间已经存在Man
use space\Man as M;
use function space\display as dis;
use const space\PI as D;

3. Used for the introduction of trait feature capabilities

<?php
trait A{
    function testTrait(){
        echo &#39;This is Trait A!&#39;;
    }
}

class B {
    use A;
}

$b = new B();
$b->testTrait();

?>

4. In anonymous functions Reference local variables in

<?php 
function F1(){
    $ok="HelloWorld";
    $a=function() use($ok) {
        echo "$ok";
    };
    $a();
}
F1();
?>

Recommended: 《2021 PHP interview questions summary (collection)》《php video tutorial 》

The above is the detailed content of Use keyword in various aspects of life in PHP. For more information, please follow other related articles on the PHP Chinese website!