Your First Swift 4 & iOS 11 App - Part 31: | Ray Wenderlich

Try this challenge to make sure you understand the difference between local and instance variables, which is a common point of confusion for beginners to programming.

This is a companion discussion topic for the original entry at

video 31 doesn’t play

safari on mac os high sierra

also, i keep my hand on the volume buttons more than i’d like
please use sound compression and sound limiters on your lectures
i’d love to help with that as i’m a software developer AND a music producer:
contact me regrading improving your audio please :

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Thank you - we will investigate!

I thought I understood the concept of local v. instance variables, but got confused when you started calling the “Let” (message, difference, etc) VARIABLES.

If these “Let” values (which are constants?) are changing, then what’s the real difference between a constant and a variable"??

Please explain.

Absolutely loving the course!!

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