Regular expression for percentages greater than 0 and less than or equal to 100

Question

I searched the web and came up with: /(^100(\\.0{1,2})?$)|(^([1-9]([0-9])?|0)(\\.[0-9]{1,2})?$)/

The problem is it accepts 0.

Answer 1

Perhaps you are thinking about the problem wrongly. A better method if possible would be to convert the string to a double and perform the check using arithmetic operators .

const examplePercentage = '0.5%';
const percentageAsFloat = parseFloat(examplePercentage); // 0.5
const isValid = percentageAsFloat > 0 && percentageAsFloat <= 100; // true

Answer 2

Try this one:

^0*(100(\.0{1,2})?|[1-9][0-9]?(\.[0-9]{1,2})?|0\.(0[1-9]|[1-9][0-9]?))$

It handles >= 1 different from < 1 .

But I would go with parsing the number and checking it's value.