Simple regular expression for a decimal with a precision of 2
What is the regular expression for a decimal with a precision of 2?
Valid examples:
123.12
2
56754
92929292929292.12
0.21
3.1
Invalid examples:
12.1232
2.23332
e666.76
The decimal point may be optional, and integers may also be included.
Answer
Valid regex tokens vary by implementation. A generic form is:
[0-9]+(\.[0-9][0-9]?)?
More compact:
\d+(\.\d{1,2})?
Both assume that both have at least one digit before and one after the decimal place.
To require that the whole string is a number of this form, wrap the expression in start and end tags such as (in Perl's form):
^\d+(\.\d{1,2})?$
To match numbers without a leading digit before the decimal (.12) and whole numbers having a trailing period (12.) while excluding input of a single period (.), try the following:
^(\d+(\.\d{0,2})?|\.?\d{1,2})$
Added
Wrapped the fractional portion in ()? to make it optional. Be aware that this excludes forms such as 12. Including that would be more like ^\d+\\.?\d{0,2}$.
Added
Use ^\d{1,6}(\.\d{1,2})?$ to stop repetition and give a restriction to whole part of the decimal value.