Exercise: Regexes part 2

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Write functions that returns true if the given value is a

• Hexadecimal number
• Octal number
• Binary number

Write a function that given a string it return true if the string is a number. As there might be several definitions of what is the number create several solutions one for each definition:

• Non negative integer.
• Integer. (Will you also allow + in front of the number or only - ?
• Real number. (Do you allow .3 ? What about 2. ?
• In scientific notation. (something like this: 2.123e4 )

examples/regex/which_are_numbers.txt

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2.3
2.3.4
2.4e3
abc