Prob due to the NetSuite docs always having this at the top.

Hmm do they? I've never noticed, but yes that would provide one strong possibility

Yeah all the time I looked at examples they always had these at the top.

I totally understand an alias if you have a really deep reference like

level1.anotherLevel.yetanotherlevel.somecrazynesting.omgsrsly.thePropertyYouActuallyWant

Yeah I've gotta brush up on my chaining but keeping them separate does look tidy sometimes.

but I don't understand aliasing

context.line

to

line

I had to split things out in a MR once while using underscore as when chained it just wouldn't work due to the processing time and the amount of data it was processing.

Exactly as @karlenigma said, its part of the documentation, though I'm sure with more experience I'll recognize when it's needed or not

I often alias

var rec = context.currentRecord;

or

var rec = context.newRecord;

to abbreviate my code, but generally only if I have a lot of references to the record object. If I only reference the object once it's not as useful to alias it.