PHP之Trait功能与用法实例分析

本文实例讲述了PHP Trait功能与用法。分享给大家供大家参考，具体如下：

Trait 是为类似 PHP 的单继承语言而准备的一种代码复用机制。

1.如果引入的Trait有同名的方法

trait A{
 public function eat(){
  echo 'A-eat';
 }
 
 public function say(){
  echo 'A-say';
 }
}
 
trait B{
 
 public function eat(){
  echo 'B-eat';
 }
 
 public function say(){
  echo 'B-say';
 }
}
 
class People{
 use A,B{
  A::eat insteadof B;
  B::eat as eatbak;
  B::say insteadof A;
 }
}
 
$people = new People();
$people->eat();
echo "<br/>";
$people->say();
echo "<br/>";
$people->eatbak();

运行结果：

A-eat
B-say
B-eat

2.修改访问控制

<?php
trait Test {
 public function say() {
  echo 'say hello';
 }
}
 
class People {
 use Test { say as protected; }
}
 
$people = new People();
 
$people->say();

运行结果：

Fatal error: Call to protected method People::say() from context '' in D:\phpdemo\trait_Demo.php on line 14

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