Positive integers between 1 and 100 regular
Expression: ^[1-9]\d?$|^100$
explain:
^ indicates the starting position of the matching string
[1-9] represents any one of the numbers 1-9
\d means any number
? Represents 0 or 1 occurrence of the preceding character or subexpression
$ indicates the end position of the matching string
| means or
The final interpretation is: match a string that satisfies the following conditions:
Start with a number from 1-9 and can be followed by 0 or 1 number, or 100
Positive integers between 20 and 100 regular
Expression: ^([2-9]\d|[1-9]\d{2})(?<=99|00)$
explain:
^ Indicates the start position of the matched string
() represents a capture group for extracting matched content
[2-9] represents any one of the numbers 2-9
\d means any number
| means or
[1-9]\d{2} means a three-digit number starting with the digits 1-9 followed by two arbitrary digits
(?<=99|00) indicates that it ends with 99 or 00, using a look-ahead assertion
$ indicates the end position of the matched string
The final interpretation is: match a string that satisfies the following conditions:
Start with a number in the number 2-9, followed by any number, and the number range is between 20-99; or start with a number 1-9, followed by two numbers, and the number range is between 100-999 and end with 99 or 00.
Regex to keep 2 decimal places
Regular expression: ^[0-9]+(.[0-9]{1,2})?$
explain:
^ Indicates the beginning of the matched string
[0-9]+ means match at least one digit
(.[0-9]{1,2})? Indicates an optional decimal part, where . means to match the decimal point, and [0-9]{1,2} means to match the decimal part of one or two digits
$ indicates the end position of the matched string
The final interpretation is: match a number or a decimal, the decimal has at most two decimal parts, and the decimal point and the integer part are not necessary.