CODEWITHSUNDEEP
smalltalkgnu-smalltalk
MarksCode
MarksCode

Reputation: 8584

Smalltalk weird printing error

In order to "pad" a number I'm printing so that it's always a fixed number of characters, I'm making a padding string based off how many integers and in the given number:

pad := '    '.
(freqVal < 10) ifTrue: [ pad := '   ' ].
((freqVal < 100) & (freqVal > 9)) ifTrue: [ pad := '  ' ].
((freqVal < 1000) & (freqVal > 99)) ifTrue: [ pad := ' ' ].
stdout<<pad<<freqVal<<<<nl

However, the printed result always makes the variable pad into a letter instead of spaces like I'm assigning its value to. If I add pad displayNl before the last line it prints out a letter for some reason instead of just spaces.

Any ideas why this might be occurring?

Upvotes: 0

Views: 118

Answers (1)

Tom
Tom

Reputation: 168

I don't know Gnu-Smalltalk in particular. Surely there are some handy String methods or formatters you could reuse for this purpose though. My advice would be to first convert the number into a String and then format it with blank-padding. That way you will avoid type conversion Problems which you've experienced

new String method (preferrably an existing one in your ST Distribution):

withLeading: aCharacter size: anInteger
   (anInteger < self size) ifTrue: [^self copyFrom: 1 to: anInteger].
   ^((self species new: anInteger - self size) atAllPut: aCharacter ), self

usage example

9 asString withLeading: ($ ) size: 10           "result '         9'"
10 asString withLeading: ($ ) size: 10          "result '        10'"
999 asString withLeading: ($ ) size: 10         "result '       999'"

Upvotes: 2

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