12 Positive integer (without a leading + sign) +123 Positive integer (with a leading + sign) -456 Negative integer 0 Zero +0 Zero, with a leading + -0 Zero, with a leading -
12.0 This is a
, not an , though it represents an integer. 12. Decimal points are not allowed. +---12 Only one leading +/- is allowed. ten Letters are not allowed. _5 Special characters are not allowed. \35 Escaped Unicode characters are not allowed, even if they are an integer (here: 5). \4E94 Non-arabic numerals are not allowed, even when escaped (here: the Japanese 5, 五). 3e4 Scientific notation is not allowed.