r - Printing values inside for loop gives different results if you print by index or by value -

i'm trying understand why different results when print values of list when access them index or directly:

ws <- c(as.date('2016-01-01'))  (w in ws) {   print(w)   } # prints 16801  (idx in 1:length(ws)) {   print(ws[idx]) } # prints 2016-01-01 

i'm not sure why first time, when access value using in wrong value.

how can print values directly accessing via in (not using indexes)? , why happening?

probably because ws integer; "date" see printing purposes, data tracked days since starting point.

when create indexing variable w in ws, r coercing integer w has lost "date" attributes, , underlying integer.

indeed, in ?control see seq:

an expression evaluating vector (including list , expression) or pairlist or null. factor value coerced character vector.

and as.vector(ws) return ws it's underlying, integer, state.

in second example, ws has remained unchanged, printing elements continue formatted dates.