files/fa/web/javascript/reference/errors/unexpected_token/index.html


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---
title: 'SyntaxError: Unexpected token'
slug: Web/JavaScript/Reference/Errors/Unexpected_token
translation_of: Web/JavaScript/Reference/Errors/Unexpected_token
---
<div class="twocolumns">

</div>

<div class="threecolumns">
<p>{{jsSidebar("Errors")}}</p>
</div>

<p>The JavaScript exceptions "unexpected token" occur when a specific language construct was expected, but something else was provided. This might be a simple typo.</p>

<h2 id="Message">Message</h2>

<pre class="syntaxbox notranslate">SyntaxError: expected expression, got "x"
SyntaxError: expected property name, got "x"
SyntaxError: expected target, got "x"
SyntaxError: expected rest argument name, got "x"
SyntaxError: expected closing parenthesis, got "x"
SyntaxError: expected '=&gt;' after argument list, got "x"
</pre>

<h2 id="Error_type">Error type</h2>

<p>{{jsxref("SyntaxError")}}</p>

<h2 id="What_went_wrong">What went wrong?</h2>

<p>A specific language construct was expected, but something else was provided. This might be a simple typo.</p>

<h2 id="Examples">Examples</h2>

<h3 id="Expression_expected">Expression expected</h3>

<p>For example, when chaining expressions, trailing commas are not allowed.</p>

<pre class="brush: js example-bad notranslate">for (let i = 0; i &lt; 5,; ++i) {
  console.log(i);
}
// SyntaxError: expected expression, got ')'
</pre>

<p>Correct would be omitting the comma or adding another expression:</p>

<pre class="brush: js example-good notranslate">for (let i = 0; i &lt; 5; ++i) {
  console.log(i);
}
</pre>

<h3 id="Not_enough_brackets">Not enough brackets</h3>

<p>Sometimes, you leave out brackets around <code>if</code> statements:</p>

<pre class="brush: js example-bad line-numbers  language-js notranslate">function round(n, upperBound, lowerBound){
  if(n &gt; upperBound) || (n &lt; lowerBound){
    throw 'Number ' + String(n) + ' is more than ' + String(upperBound) + ' or less than ' + String(lowerBound);
  }else if(n &lt; ((upperBound + lowerBound)/2)){
    return lowerBound;
  }else{
    return upperBound;
  }
} // SyntaxError: expected expression, got '||'</pre>

<p>The brackets may look correct at first, but note how the <code>||</code> is outside the brackets. Correct would be putting brackets around the <code>||</code>:</p>

<pre class="brush: js example-good notranslate">function round(n, upperBound, lowerBound){
  if((n &gt; upperBound) || (n &lt; lowerBound)){
    throw 'Number ' + String(n) + ' is more than ' + String(upperBound) + ' or less than ' + String(lowerBound);
  }else if(n &lt; ((upperBound + lowerBound)/2)){
    return lowerBound;
  }else{
    return upperBound;
  }
}
</pre>

<h2 id="See_also">See also</h2>

<ul>
 <li>{{jsxref("SyntaxError")}}</li>
</ul>