You can avoid the hassle of thinking of (absolute) addresses... As @Gordon mentions, allocation an Uint8Array (at the begin of your code) and using all kinds of views are a very easy and convenient way to do what you might want to do... (Nothing wrong with praying... - it's a very wise thing... just not for covering up subpar choices...)
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
You can avoid the hassle of thinking of (absolute) addresses... As @Gordon mentions, allocation an Uint8Array (at the begin of your code) and using all kinds of views are a very easy and convenient way to do what you might want to do... (Nothing wrong with praying... - it's a very wise thing... just not for covering up subpar choices...)