# 4种回调函数的写法 ## **1、匿名函数** ``` <pre class="calibre10">``` $server<span class="token1">-</span><span class="token1">></span><span class="token4">on</span><span class="token3">(</span><span class="token2">'Request'</span><span class="token3">,</span> <span class="token5">function</span> <span class="token3">(</span>$req<span class="token3">,</span> $resp<span class="token3">)</span> use <span class="token3">(</span>$a<span class="token3">,</span> $b<span class="token3">,</span> $c<span class="token3">)</span> <span class="token3">{</span> echo <span class="token2">"hello world"</span><span class="token3">;</span> <span class="token3">}</span><span class="token3">)</span><span class="token3">;</span> ``` ``` > 可使用`use`向匿名函数传递参数 ## **2、类静态方法** ``` <pre class="calibre10">``` class <span class="token4">A</span> <span class="token3">{</span> static <span class="token5">function</span> <span class="token4">test</span><span class="token3">(</span>$req<span class="token3">,</span> $resp<span class="token3">)</span> <span class="token3">{</span> echo <span class="token2">"hello world"</span><span class="token3">;</span> <span class="token3">}</span> <span class="token3">}</span> $server<span class="token1">-</span><span class="token1">></span><span class="token4">on</span><span class="token3">(</span><span class="token2">'Request'</span><span class="token3">,</span> <span class="token2">'A::Test'</span><span class="token3">)</span><span class="token3">;</span> $server<span class="token1">-</span><span class="token1">></span><span class="token4">on</span><span class="token3">(</span><span class="token2">'Request'</span><span class="token3">,</span> <span class="token4">array</span><span class="token3">(</span><span class="token2">'A'</span><span class="token3">,</span> <span class="token2">'Test'</span><span class="token3">)</span><span class="token3">)</span><span class="token3">;</span> ``` ``` > 对应的静态方法必须为`public` ## **3、函数** ``` <pre class="calibre10">``` <span class="token5">function</span> <span class="token4">my_onRequest</span><span class="token3">(</span>$req<span class="token3">,</span> $resp<span class="token3">)</span> <span class="token3">{</span> echo <span class="token2">"hello world"</span><span class="token3">;</span> <span class="token3">}</span> $server<span class="token1">-</span><span class="token1">></span><span class="token4">on</span><span class="token3">(</span><span class="token2">'Request'</span><span class="token3">,</span> <span class="token2">'my_onRequest'</span><span class="token3">)</span><span class="token3">;</span> ``` ``` ## **4、对象方法** ``` <pre class="calibre10">``` class <span class="token4">A</span> <span class="token3">{</span> <span class="token5">function</span> <span class="token4">test</span><span class="token3">(</span>$req<span class="token3">,</span> $resp<span class="token3">)</span> <span class="token3">{</span> echo <span class="token2">"hello world"</span><span class="token3">;</span> <span class="token3">}</span> <span class="token3">}</span> $object <span class="token1">=</span> <span class="token5">new</span> <span class="token4">A</span><span class="token3">(</span><span class="token3">)</span><span class="token3">;</span> $server<span class="token1">-</span><span class="token1">></span><span class="token4">on</span><span class="token3">(</span><span class="token2">'Request'</span><span class="token3">,</span> <span class="token4">array</span><span class="token3">(</span>$object<span class="token3">,</span> <span class="token2">'test'</span><span class="token3">)</span><span class="token3">)</span><span class="token3">;</span> ``` ``` > 对应的方法必须为`public`