PHP 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