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<qhelp>

<overview>

<p>

If a condition always evaluates to true or always evaluates to false, this often indicates

incomplete code or a latent bug and should be examined carefully.

</p>

</overview>

<recommendation>

<p>

Examine the surrounding code to determine why the condition is useless. If it is no

longer needed, remove it.

</p>

</recommendation>

<example>

<p>

The following example constructs an array <code>lines</code>, and then attempts to check whether

it has any elements by means of an if conditional <code>if (!lines)</code>.

</p>

<sample src="examples/UselessConditional.js" />

<p>

Note that in JavaScript (unlike some other languages) arrays and objects are always considered to

be true when evaluated in a Boolean context. The code should instead check <code>lines.length</code>:

</p>

<sample src="examples/UselessConditionalGood.js" />

</example>

<references>

<li>Mozilla Developer Network: <a href="https://developer.mozilla.org/en-US/docs/Glossary/Truthy">Truthy</a>,

<a href="https://developer.mozilla.org/en-US/docs/Glossary/Falsy">Falsy</a>.</li>

</references>

</qhelp>