Consider raising attention to the potential ambiguity of the assignment arrow (<-) operator.

[massaraevi]

In the section "Intro to R" of the Instructor Notes, the assignment arrow operator (<-) is discussed. This is a good point to warn readers of the potential ambiguity of the operator in R. Since the operator consists of a symbol that resembles the "less than" comparison operator (<) and the minus symbol (-) for subtraction, if we have a logical expression like x<-5 (is x less than -5), the R interpretor may interpret this instruction as an assignment of 5 to x. In this case, the solution (and the general good coding practices recommendation) is to use spaces to reduce ambiguity. Therefore, if the intention is for a logical expression, it should be written as "x < -5" or if the assignment is intended, it should be "x <- 5".

[juanfung]

hi @massaraevi thank you for the observation! i think an additional bullet explaining this would be a nice addition to the instructor notes. would you be interested in submitting a PR?

[fengxia9]

I think this is a good catch. Anytime, the <- together would be the assignment arrow operator.

[mbplatt]

The spacing would certainly work, however, I think novices often have difficulty differentiating between when spaces matter and when they do not. This could be potentially confusing. An alternative would be to place the negative number in parentheses "x < (-5)". That would make it easier to differentiate between the two.

[Dr-Ivis-Renee-King]

Hi @mbplatt, this suggestion seems like a good example for novice learners to practice using the assignment operator. I believe it would be a good alternative to include it as a Note for the instructor along with a tip to use the shortcut feature for the assignment operator. So the learner will distinguish wanting to use the operator instead of assigning x to -5.

[jdrasmus1]

Looking at the lesson, I thought of few ways this could be clarified, depending on how generally it to be addressed:

1. Simple parenthetical for example on line 60: "in syntax, it is good practice to always use <- for assignments (note the spaces before and after the arrow)."
2. More general clarification in the paragraph below about style for objects, e.g. on line 71: "You want your object names to be explicit and not too long. Generally, objects are separated from other objects and operators (like the the <- arrow) with spaces so cannot include spaces."
3. An even more note for the instructor that normalizes typos with quotations, parentheses, capitalization, and spaces.

[juanfung]

@jdrasmus1 that all sounds good to me. would you be interested in submitting a PR with those changes?