Hi folks.
I'm starting in Pharo studies by FUN Mooc.
In Week 03, on An Overview of Essential Collections there is the example below:

| days |
days := Dictionary new.

days
at: #January put: 31;
at: #February put: 28;
at: #March put: 31.

days keysAndValuesDo:
[ :k :v | Transcript show: k asString, ' has ', v printString, ' days'
; cr ]

The code in blue I change for��

days keysAndValuesDo:
[ :k :v | Transcript show: k asString, ' has ', v asString, ' days'
; cr ]

And works too on Playground.

There is something different about both? There is someone better than other?

Thanks in advance,

Samuel T. Santos