Passing variable in parent scope to callback function

Question

This is more of a JavaScript Closure question than a Firebase question. In the following code, the Firebase callback isn\'t recognizing the variable myArr in the parent scop

Answer 1

The child_added event is not immediately executed, therefore is not synchronous and you can't rely on it to have executed, before the log call at the end of your function.

The procedure is:

• Define myArr
• Instantiate Firebase
• Assign event handler for child_added
• Log the value of myArr
• Return myArr - end of function
• Now at some point after this, the child_added event is fired, which pushes to your array, but as you can see, your show_fb() function has already finished executing by this point.