<li class="tsd-description">
<div class="tsd-comment tsd-typography"><p>Synchronously calls each of the listeners registered for the event named<code>eventName</code>, in the order they were registered, passing the supplied arguments
to each.</p>
<p>Returns <code>true</code> if the event had listeners, <code>false</code> otherwise.</p>
<pre><code class="language-js"><span class="hl-4">const</span><span class="hl-0"> </span><span class="hl-5">EventEmitter</span><span class="hl-0"> = </span><span class="hl-2">require</span><span class="hl-0">(</span><span class="hl-6">'events'</span><span class="hl-0">);</span><br/><span class="hl-4">const</span><span class="hl-0"> </span><span class="hl-5">myEmitter</span><span class="hl-0"> = </span><span class="hl-4">new</span><span class="hl-0"> </span><span class="hl-2">EventEmitter</span><span class="hl-0">();</span><br/><br/><span class="hl-7">// First listener</span><br/><span class="hl-3">myEmitter</span><span class="hl-0">.</span><span class="hl-2">on</span><span class="hl-0">(</span><span class="hl-6">'event'</span><span class="hl-0">, </span><span class="hl-4">function</span><span class="hl-0"> </span><span class="hl-2">firstListener</span><span class="hl-0">() {</span><br/><span class="hl-0"> </span><span class="hl-3">console</span><span class="hl-0">.</span><span class="hl-2">log</span><span class="hl-0">(</span><span class="hl-6">'Helloooo! first listener'</span><span class="hl-0">);</span><br/><span class="hl-0">});</span><br/><span class="hl-7">// Second listener</span><br/><span class="hl-3">myEmitter</span><span class="hl-0">.</span><span class="hl-2">on</span><span class="hl-0">(</span><span class="hl-6">'event'</span><span class="hl-0">, </span><span class="hl-4">function</span><span class="hl-0"> </span><span class="hl-2">secondListener</span><span class="hl-0">(</span><span class="hl-3">arg1</span><span class="hl-0">, </span><span class="hl-3">arg2</span><span class="hl-0">) {</span><br/><span class="hl-0"> </span><span class="hl-3">console</span><span class="hl-0">.</span><span class="hl-2">log</span><span class="hl-0">(</span><span class="hl-6">`event with parameters </span><span class="hl-4">${</span><span class="hl-3">arg1</span><span class="hl-4">}</span><span class="hl-6">, </span><span class="hl-4">${</span><span class="hl-3">arg2</span><span class="hl-4">}</span><span class="hl-6"> in second listener`</span><span class="hl-0">);</span><br/><span class="hl-0">});</span><br/><span class="hl-7">// Third listener</span><br/><span class="hl-3">myEmitter</span><span class="hl-0">.</span><span class="hl-2">on</span><span class="hl-0">(</span><span class="hl-6">'event'</span><span class="hl-0">, </span><span class="hl-4">function</span><span class="hl-0"> </span><span class="hl-2">thirdListener</span><span class="hl-0">(...</span><span class="hl-3">args</span><span class="hl-0">) {</span><br/><span class="hl-0"> </span><span class="hl-4">const</span><span class="hl-0"> </span><span class="hl-5">parameters</span><span class="hl-0"> = </span><span class="hl-3">args</span><span class="hl-0">.</span><span class="hl-2">join</span><span class="hl-0">(</span><span class="hl-6">', '</span><span class="hl-0">);</span><br/><span class="hl-0"> </span><span class="hl-3">console</span><span class="hl-0">.</span><span class="hl-2">log</span><span class="hl-0">(</span><span class="hl-6">`event with parameters </span><span class="hl-4">${</span><span class="hl-3">parameters</span><span class="hl-4">}</span><span class="hl-6"> in third listener`</span><span class="hl-0">);</span><br/><span class="hl-0">});</span><br/><br/><span class="hl-3">console</span><span class="hl-0">.</span><span class="hl-2">log</span><span class="hl-0">(</span><span class="hl-3">myEmitter</span><span class="hl-0">.</span><span class="hl-2">listeners</span><span class="hl-0">(</span><span class="hl-6">'event'</span><span class="hl-0">));</span><br/><br/><span class="hl-3">myEmitter</span><span class="hl-0">.</span><span class="hl-2">emit</span><span class="hl-0">(</span><span class="hl-6">'event'</span><span class="hl-0">, </span><span class="hl-1">1</span><span class="hl-0">, </span><span class="hl-1">2</span><span class="hl-0">, </span><span class="hl-1">3</span><span class="hl-0">, </span><span class="hl-1">4</span><span class="hl-0">, </span><span class="hl-1">5</span><span class="hl-0">);</span><br/><br/><span class="hl-7">// Prints:</span><br/><span class="hl-7">// [</span><br/><span class="hl-7">// [Function: firstListener],</span><br/><span class="hl-7">// [Function: secondListener],</span><br/><span class="hl-7">// [Function: thirdListener]</span><br/><span class="hl-7">// ]</span><br/><span class="hl-7">// Helloooo! first listener</span><br/><span class="hl-7">// event with parameters 1, 2 in second listener</span><br/><span class="hl-7">// event with parameters 1, 2, 3, 4, 5 in third listener</span>
<li class="tsd-description">
<div class="tsd-comment tsd-typography"><p>Synchronously calls each of the listeners registered for the event named<code>eventName</code>, in the order they were registered, passing the supplied arguments
to each.</p>
<p>Returns <code>true</code> if the event had listeners, <code>false</code> otherwise.</p>
<pre><code class="language-js"><span class="hl-4">const</span><span class="hl-0"> </span><span class="hl-5">EventEmitter</span><span class="hl-0"> = </span><span class="hl-2">require</span><span class="hl-0">(</span><span class="hl-6">'events'</span><span class="hl-0">);</span><br/><span class="hl-4">const</span><span class="hl-0"> </span><span class="hl-5">myEmitter</span><span class="hl-0"> = </span><span class="hl-4">new</span><span class="hl-0"> </span><span class="hl-2">EventEmitter</span><span class="hl-0">();</span><br/><br/><span class="hl-7">// First listener</span><br/><span class="hl-3">myEmitter</span><span class="hl-0">.</span><span class="hl-2">on</span><span class="hl-0">(</span><span class="hl-6">'event'</span><span class="hl-0">, </span><span class="hl-4">function</span><span class="hl-0"> </span><span class="hl-2">firstListener</span><span class="hl-0">() {</span><br/><span class="hl-0"> </span><span class="hl-3">console</span><span class="hl-0">.</span><span class="hl-2">log</span><span class="hl-0">(</span><span class="hl-6">'Helloooo! first listener'</span><span class="hl-0">);</span><br/><span class="hl-0">});</span><br/><span class="hl-7">// Second listener</span><br/><span class="hl-3">myEmitter</span><span class="hl-0">.</span><span class="hl-2">on</span><span class="hl-0">(</span><span class="hl-6">'event'</span><span class="hl-0">, </span><span class="hl-4">function</span><span class="hl-0"> </span><span class="hl-2">secondListener</span><span class="hl-0">(</span><span class="hl-3">arg1</span><span class="hl-0">, </span><span class="hl-3">arg2</span><span class="hl-0">) {</span><br/><span class="hl-0"> </span><span class="hl-3">console</span><span class="hl-0">.</span><span class="hl-2">log</span><span class="hl-0">(</span><span class="hl-6">`event with parameters </span><span class="hl-4">${</span><span class="hl-3">arg1</span><span class="hl-4">}</span><span class="hl-6">, </span><span class="hl-4">${</span><span class="hl-3">arg2</span><span class="hl-4">}</span><span class="hl-6"> in second listener`</span><span class="hl-0">);</span><br/><span class="hl-0">});</span><br/><span class="hl-7">// Third listener</span><br/><span class="hl-3">myEmitter</span><span class="hl-0">.</span><span class="hl-2">on</span><span class="hl-0">(</span><span class="hl-6">'event'</span><span class="hl-0">, </span><span class="hl-4">function</span><span class="hl-0"> </span><span class="hl-2">thirdListener</span><span class="hl-0">(...</span><span class="hl-3">args</span><span class="hl-0">) {</span><br/><span class="hl-0"> </span><span class="hl-4">const</span><span class="hl-0"> </span><span class="hl-5">parameters</span><span class="hl-0"> = </span><span class="hl-3">args</span><span class="hl-0">.</span><span class="hl-2">join</span><span class="hl-0">(</span><span class="hl-6">', '</span><span class="hl-0">);</span><br/><span class="hl-0"> </span><span class="hl-3">console</span><span class="hl-0">.</span><span class="hl-2">log</span><span class="hl-0">(</span><span class="hl-6">`event with parameters </span><span class="hl-4">${</span><span class="hl-3">parameters</span><span class="hl-4">}</span><span class="hl-6"> in third listener`</span><span class="hl-0">);</span><br/><span class="hl-0">});</span><br/><br/><span class="hl-3">console</span><span class="hl-0">.</span><span class="hl-2">log</span><span class="hl-0">(</span><span class="hl-3">myEmitter</span><span class="hl-0">.</span><span class="hl-2">listeners</span><span class="hl-0">(</span><span class="hl-6">'event'</span><span class="hl-0">));</span><br/><br/><span class="hl-3">myEmitter</span><span class="hl-0">.</span><span class="hl-2">emit</span><span class="hl-0">(</span><span class="hl-6">'event'</span><span class="hl-0">, </span><span class="hl-1">1</span><span class="hl-0">, </span><span class="hl-1">2</span><span class="hl-0">, </span><span class="hl-1">3</span><span class="hl-0">, </span><span class="hl-1">4</span><span class="hl-0">, </span><span class="hl-1">5</span><span class="hl-0">);</span><br/><br/><span class="hl-7">// Prints:</span><br/><span class="hl-7">// [</span><br/><span class="hl-7">// [Function: firstListener],</span><br/><span class="hl-7">// [Function: secondListener],</span><br/><span class="hl-7">// [Function: thirdListener]</span><br/><span class="hl-7">// ]</span><br/><span class="hl-7">// Helloooo! first listener</span><br/><span class="hl-7">// event with parameters 1, 2 in second listener</span><br/><span class="hl-7">// event with parameters 1, 2, 3, 4, 5 in third listener</span>