PHPのマジック定数の詳しい説明

<?php

echo __LINE__."<br>";//3

echo __LINE__."<br>";//5

?>

<?php
        echo __FILE__."<br>";//F:\learnlog\zend\php\magic.php
?>

<?php
        echo __DIR__."<br>";//F:\learnlog\zend\php
?>

<?php
function sum(){
    echo __METHOD__."<br>";
}
sum();//输出：sum
?>

<?php
class People{
  
  static function sum(){
     echo __CLASS__;
  }
}
People::sum();//People
?>

<?php
namespace Controller;
class People{
  
  static function sum(){
     echo __NAMESPACE__;
  }
}
People::sum();//Controller
?>

<?php
trait A{
     function traitName() 
     {echo __TRAIT__;}
 }
 trait B {
     use A;
 }
 class Test {
     use B;
 }
 (new Test)->traitName(); //A
?>