如果多个Trait中包含同名方法或者属性时，会怎样呢？答案是当组合的多个Trait包含同名属性或者方法时，需要明确声明解决冲突，否则会产生一个致命错误。
<?php
trait Trait1 {
public function hello() {
echo "Trait1::hello\n";
}
public function hi() {
echo "Trait1::hi\n";
}
}
trait Trait2 {
public function hello() {
echo "Trait2::hello\n";
}
public function hi() {
echo "Trait2::hi\n";
}
}
class Class1 {
use Trait1, Trait2;
}
//输出：Fatal error: Trait method hello has not been applied, because there are collisions with other trait methods on Class1 in使用insteadof和as操作符来解决冲突，insteadof是使用某个方法替代另一个，而as是给方法取一个别名，具体用法请看代码:
<?php
trait Trait1 {
public function hello() {
echo "Trait1::hello \n";
}
public function hi() {
echo "Trait1::hi \n";
}
}
trait Trait2 {
public function hello() {
echo "Trait2::hello\n";
}
public function hi() {
echo "Trait2::hi\n";
}
}
class Class1 {
use Trait1, Trait2 {
Trait2::hello insteadof Trait1;
Trait1::hi insteadof Trait2;
}
}
class Class2 {
use Trait1, Trait2 {
Trait2::hello insteadof Trait1;
Trait1::hi insteadof Trait2;
Trait2::hi as hei;
Trait1::hello as hehe;
}
}
$Obj1 = new Class1();
$Obj1->hello();
$Obj1->hi();
echo "\n";
$Obj2 = new Class2();
$Obj2->hello();
$Obj2->hi();
$Obj2->hei();
$Obj2->hehe();输出结果：
Trait2::hello Trait1::hi Trait2::hello Trait1::hi Trait2::hi Trait1::hello
