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class Integer
Parent: Numeric
Version: 1.6

Index:

chr downto integer? next step succ times upto

Bignum, Fixnum

Integer is the basis for the two concrete classes that hold whole numbers, Bignum and Fixnum.

instance methods
chr int.chr -> aString
Returns a string containing the ASCII character represented by the receiver's value.

65.chr -> "A"
?a.chr -> "a"
230.chr -> "\346"

downto int.downto( anInteger ) {| i | block } -> int
Iterates block, passing decreasing values from int down to and including anInteger. 

5.downto(1) { |n| print n, ".. " }
print "  Liftoff!\n"

produces: 

5.. 4.. 3.. 2.. 1..   Liftoff!

integer? int.integer? -> true
Always returns true.
next int.next -> anInteger
Returns the Integer equal to int + 1.

1.next -> 2
(-1).next -> 0

step int.step( endNum, step ) {| i | block } -> int
Invokes block with the sequence of numbers starting at int, incremented by step on each call. The loop finishes when the value to be passed to the block is greater than endNum (if step is positive) or less than endNum (if step is negative). 

1.step(10, 2) { |i| print i, " " }

produces: 

1 3 5 7 9

succ int.succ -> anInteger
Synonym for Integer#next.
times int.times {| i | block } -> int
Iterates block int times, passing in values from zero to int - 1. 

5.times do |i|
  print i, " "
end
print "\n"

produces: 

0 1 2 3 4

upto int.upto( anInteger ) {| i | block } -> int
Iterates block, passing in integer values from int up to and including anInteger. 

5.upto(10) { |i| print i, " " }

produces: 

5 6 7 8 9 10

Extracted from the book "Programming Ruby - The Pragmatic Programmer's Guide"
Copyright © 2000 Addison Wesley Longman, Inc. Released under the terms of the Open Publication License V1.0.
This reference is available for download.