Scared to think about it? About the third parameter of in_array

Use in_array () Determine whether there is a certain value in the array. If the third parameter is omitted, sometimes the result may be meaningless...

For example, the following Code snippet:

<?php
$arr = [true, false];
$f = in_array(&#39;Hello&#39;, $arr);
if($f)
  echo &#39;in array&#39;;
else
  echo &#39;not found&#39;;
//结果输出 in array

Changed to in_array('Hello', $arr, true) This problem can be solved

This problem does not exist in JS, for example, use The indexOf () function can be rewritten like this

I don’t know if this question will make you fall into silence→_→

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