I look for a regular expression to support double number with just one fraction part which ranges between 0.1 to 999.9
It means following values are not allowed:
0
0.0 // less than lower bound
0.19 // fraction part is 2 digits, right '9' is extra
94.11 // fraction part is 2 digits, right '1' is extra
999.90 // fraction part is 2 digits, '0' is extra
9.0 // should be 9 or 9.1, 9.0 is wrong
1000 // is higher than upper bound
allowed ones:
1.1
55.5
999.9
My regular expression is:
(^(\.[1-9])?$|(^[1-9][0-9]{0,2}?(\.[1-9])?$))$
Which doesn't support 0.1 to 0.9 and extra zeros like 99.000 and 99.0
Test steps: In your browser console:
var reg = new RegExp(/(^(\.[1-9])?$|(^[1-9][0-9]{0,2}?(\.[1-9])?$))$/);
reg.test(12);
Any help appriciated
I guess this is the most accurate:
/^(0\.[1-9]|[1-9][0-9]{0,2}(\.[1-9])?)$/
Note that you don't need the RegExp constructor when working with regex literals:
re = /^(0\.[1-9]|[1-9][0-9]{0,2}(\.[1-9])?)$/
a = [0, 0.1, 123, 123.4, '00.1', 123.45, 123456, 'foo']
a.map(function(x) { console.log(x, re.test(x)) })
0 false
0.1 true
123 true
123.4 true
00.1 false
123.45 false
123456 false
foo false