Characters in Smalltalk

$-prefixed objects with their own protocol.

"Characters are objects with a $ prefix and their own protocol."
| initial |
initial := $W.
Transcript show: initial asLowercase printString; cr.
Transcript show: initial isVowel printString; cr.
Transcript show: initial asInteger printString; cr.

"Strings answer character questions element by element."
Transcript show: ('Wren42' select: [:c | c isDigit]); cr.
Transcript show: ('drop cap' collect: [:c | c asUppercase]); cr.
Transcript show: (Character value: 63) printString; cr.

How it works

1. $W is a Character; asInteger reveals the code point.
2. isVowel and isDigit answer directly.
3. Strings select and collect over their characters.

Keywords and builtins used here

• Character
• Transcript
• asInteger
• asLowercase
• asUppercase
• cr
• isDigit
• isVowel
• printString

The run, in numbers

Lines

11

Characters to type

484

Tokens

76

Three-star pace

60 tpm

At the three-star pace of 60 tokens a minute, this run takes about 76 seconds.

Type this snippet

Step 2 of 3 in Strings, step 19 of 31 in Language basics.

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