Non-decimal radices/Input: Difference between revisions
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(Add Seed7 example) |
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bin4 = "101011001" |
bin4 = "101011001" |
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dec1.to_i # => 123459 |
p dec1.to_i # => 123459 |
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hex2.hex # => 180154659 |
p hex2.hex # => 180154659 |
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oct3.oct # => 4009 |
p oct3.oct # => 4009 |
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# nothing for binary</lang> |
# nothing for binary</lang> |
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The |
The String class has '''to_i(base)''' method ( base : 2 .. 36 ). |
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Invalid characters past the end of a valid number are ignored. |
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(This method never raises an exception when base is valid.) |
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<lang ruby>p dec1.to_i(10) # => 123459 |
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p hex2.to_i(16) # => 180154659 |
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p oct3.to_i(8) # => 4009 |
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p bin4.to_i(2) # => 345 |
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p "xyz9".to_i(10) # => 0 If there is not a valid letter, 0 is returned.</lang> |
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The '''Integer()''' method can parse a string, provided the string has the right prefix: |
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p Integer("0d" + dec1) # => 123459 |
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p Integer("0x" + hex2) # => 180154659 |
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p Integer("0" + oct3) # => 4009 |
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p Integer("0o" + oct3) # => 4009 |
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p Integer("0b" + bin4) # => 345</lang> |
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So can the <code>.to_i(0)</code> method, which never raises an exception: |
So can the <code>.to_i(0)</code> method, which never raises an exception: |
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<lang ruby>dec1.to_i(0) # => 5349 (which is 12345 in octal, the 9 is discarded) |
<lang ruby>p dec1.to_i(0) # => 5349 (which is 12345 in octal, the 9 is discarded) |
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p ("0d" + dec1).to_i(0) # => 123459 |
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("0x" + hex2).to_i(0) # => 180154659 |
p ("0x" + hex2).to_i(0) # => 180154659 |
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("0" + oct3).to_i(0) # => 4009 |
p ("0" + oct3).to_i(0) # => 4009 |
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(" |
p ("0o" + oct3).to_i(0) # => 4009 |
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p ("0b" + bin4).to_i(0) # => 345</lang> |
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And then there's the poorly documented Scanf module in the Ruby stdlib, that seems to wrap the matched value in an array: |
And then there's the poorly documented Scanf module in the Ruby stdlib, that seems to wrap the matched value in an array: |
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<lang ruby>require 'scanf' |
<lang ruby>require 'scanf' |
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dec1.scanf("%d") # => [123459] |
p dec1.scanf("%d") # => [123459] |
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hex2.scanf("%x") # => [180154659] |
p hex2.scanf("%x") # => [180154659] |
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oct3.scanf("%o") # => [4009] |
p oct3.scanf("%o") # => [4009] |
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# no scanf specifier for binary numbers.</lang> |
# no scanf specifier for binary numbers.</lang> |
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