Fix hamburger menu on mobile layout: check array index

[pythonquick]

When tapping the hamburger menu icon on mobile layout, nothing happens. It turns out there's a syntax error with:

altArr[1]?.split(' ')

This fixes the ? and also checks for array index

[onweru]

@pythonquick,

The commit looks ok. However, I couldn't reproduce the bug you described. That's even without including the change you've proposed in this PR of course.

Steps to reproduce? Os, browser ... maybe even a url?

[pythonquick]

@onweru
sure, i can reproduce it by loading the Clarity demo page: https://themes.gohugo.io/theme/hugo-clarity/ on my iPhone 8 device. Tapping on the hamburger menu in the top right of the page does not expand the panel on the left. It happens both on Safari and Chrome apps on the iPhone. My iPhone is on iOS 13.3.1

The hamburger menu works fine on an my Android tablet and on my iPad.
When i load the same page on a browser on a laptop (not a mobile device), the hamburger menu works fine.
Looks like it's specific to iPhone.

[onweru]

Looks like it's specific to iPhone.

Interesting, the demo works flawlessly on my iPhone 11, iOS 14, both on safari & Firefox.

Will wait out this a while longer before merging. Thanks for bringing this up.

[onweru]

@pythonquick, thanks for contributing. Merging because, in retrospect, your change makes the code more readable.