A range of numbers is a set of numbers that falls within a certain range or span. It is defined by the minimum and maximum values of the set. For example, the range of the numbers 0, 0.1, 0.2, 0.3 ... 1 is 0 to 1. The minimum value in this range is 0, and the maximum value is 1. In this article let's understand how we can create a regex for month and how regex can be matched for a given month name.

Regex (short for regular expression) is a powerful tool used for searching and manipulating text. It is composed of a sequence of characters that define a search pattern. Regex can be used to find patterns in large amounts of text, validate user input, and manipulate strings. It is widely used in programming languages, text editors, and command line tools.

Structure of a range from 0 to 1

• Value should be a decimal number
• Value should be in range from 0 to 1
• No special characters allowed
• No other characters allowed

Regex for checking if value is in range from 0 to 1

Regular Expression for month name-

/^0.[0-9]{2}|1$/gm

Test string examples for the above regex-

Here is a detailed explanation of the above regex-

/^0.[0-9]{2}|1$/gm

1st Alternative 0.[0-9]{2}
0 matches the character 0 with index 4810 (3016 or 608) literally (case sensitive)
. matches any character (except for line terminators)
Match a single character present in the list below [0-9]
{2} matches the previous token exactly 2 times
0-9 matches a single character in the range between 0 (index 48) and 9 (index 57) (case sensitive)
2nd Alternative 1
1 matches the character 1 with index 4910 (3116 or 618) literally (case sensitive)
Global pattern flags
g modifier: global. All matches (don't return after first match)
m modifier: multi line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)

Hope this article was useful to check if the value is in range from 0 to 1 using regex.