Multidimensional array json_encode produces objects instead of arrays

The json_encode function can encode PHP arrays, and the return value is a string in json format. For json_encoding multi-dimensional arrays, I always thought it was returning an array form (in the form of {{obj1}, {obj2}, {obj3}}), but today the interface returned to the client found that it became an object instead of an array ( In the shape of [{....},{.....},{.....}]), it is inconvenient for client operations. After checking the code, I found that I had previously unset the first element of the multi-dimensional array. Units have been deleted, resulting in different return results. Look at the code below:

$arr = array(
<span style="white-space:pre">	</span>0=>array('name'=>'张三','age'=>'120'),
<span style="white-space:pre">	</span>1=>array('name'=>'李四','age'=>'111'),
<span style="white-space:pre">	</span>2=>array('name'=>'王五','age'=>'233')
);


$res = json_encode($arr);
echo "<script>console.log(&#39;$res&#39;);</script>";

The results are as follows:

Look again after removing the first index:

$arr = array(
	0=>array('name'=>'张三','age'=>'120'),
	1=>array('name'=>'李四','age'=>'111'),
	2=>array('name'=>'王五','age'=>'233')
);

unset($arr[0]); 
$res = json_encode($arr);
echo "<script>console.log(&#39;$res&#39;);</script>";

The solution is to use the sort function to index again.

$arr = array(
	0=>array('name'=>'张三','age'=>'120'),
	1=>array('name'=>'李四','age'=>'111'),
	2=>array('name'=>'王五','age'=>'233')
);

unset($arr[0]); 
sort($arr);
$res = json_encode($arr);
echo "<script>console.log(&#39;$res&#39;);</script>";

Okay... This doesn’t seem to be worth writing a blog, just think of it as a reminder to yourself

The above introduces the problem of generating objects instead of arrays after multi-dimensional array json_encode, including aspects of the problem. I hope it will be helpful to friends who are interested in PHP tutorials.