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# Regex for one word

A word is a unit of information that represents one or more letters i.e., from a-z or A-Z. In this article let's understand how we can create a regex for word and how regex can be matched for a given word.

Regex (short for regular expression) is a powerful tool used for searching and manipulating text. It is composed of a sequence of words 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 word

The word should have the following criteria and structure-

• a word is a unit of information that represents one or group of letters from a-z or A-Z
• It should contain one word.

# Regex for checking if one word is valid or not

Regular Expression for word-

/^[a-z]+$/igm  Test string examples for the above regex- Input StringMatch Output hellomatches how are you?does not match 2matches Amatches ;matches Note the i modifier in the regex takes care of the UPPERCASE letters. Here is a detailed explanation of the above regex- /^[a-z]+$/igm

^ asserts position at start of a line
Match a single word present in the list below [a-z]
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
a-z matches a single word in the range between a (index 97) and z (index 122) (case insensitive)
$asserts position at the end of a line Global pattern flags m modifier: multi line. Causes ^ and$ to match the begin/end of each line (not only begin/end of string)
g modifier: global. All matches (don't return after first match)
i modifier: insensitive. Case insensitive match (ignores case of [a-zA-Z])


Hope this article was useful to check if the string is a valid words or not.