Question

I created an array of strings in JS.

arr1 = [];
for (...)
  arr1.push('aasfd');

Now I add this array to another array contained in some other object.

arr2 = [];
arr2.push(arr1);
console.log(arr2);

The last log statement shows the expected array.

[
 Array[3]
 0: "A"
 1: "B"
 2: "C"
 length: 3
 __proto__: Array[0]
]

After a while, some event handler gets invoked and it turns out the contents of arr2 are undefined. I am pretty sure that no function in the object containing arr2 is invoked between the two callbacks.

arr2 becomes

[undefined x 1]

No idea where the array arr1 contained within arr2 is getting lost. Am I missing something? How do I debug this error?

Answer 1

I hit a bug in chrome which caused it difficult to debug the problem.

https://bugs.webkit.org/show_bug.cgi?id=35801