JSON.parse（json_string_from_php）生成奇怪的数组

I'm having a bit of difficulty with transferring a JSON object from the server to the client-side javascript

I have a rows of data fetched from MySQL query stored into $result

Here's the code:

var json = '<?= json_encode($result->fetch_all()) ?>';
var word_list = JSON.parse(json);
console.log(word_list);     //index.php:23
console.log(json);          //index.php:24

This is the result in chrome console:

Can someone tell me:
1. Why line 23 shows length of 5 when folded, then only show length of 4 when unfolded?
2. Where did word5 go? FYI, the word that disappears changes every time I refresh.

I am able to reproduce your screenshot.

I purposely hovered over the little "i" to reveal its tooltip. It states "Object state below is captured upon first expansion.

This means that if you print the array, don't expand it, modify the array (say with a pop()) then when you expand it you will see the modified array.

Demo: JSBin

console.log logs your state of the object to the console when it is hitting the console.log while inspecting the array (or any object) shows you the current state of it.

var a = [1,2,3,4,5].map(function(){ return new String(); });
console.log(a);
a.pop();