RegExp to get text in a key value pair separated by a colon

Question

I have my Regexp example here: https://regex101.com/r/kE9mZ7/1

For the following string:

key_1: some text, maybe a comma, ending in a semicolon; key_2: text

Answer 1

Here is a regex way to extract those values:

/(\w+):\s*([^;]*)/gi

or (as identifiers should begin with _ or a letter):

/([_a-z]\w*):\s*([^;]*)/gi

Here is a regex demo

var re = /([_a-z]\w*):\s*([^;]*)/gi; 
var str = 'key_1: some text, maybe a comma, ending in a semicolon; key_2: text with no ending semicolon';
while ((m = re.exec(str)) !== null) {
    document.body.innerHTML += m[1] + ": " + m[2] + "
";
}

Pattern details:

• ([_a-z]\w*) - Group 1 matching an identifier starting with _ or a letter and followed with 0+ alphanumeric/underscore symbols
• : - a colon
• \s* - 0+ whitespaces
• ([^;]*) - 0+ characters other than ;. The use of a negated character class eliminates the need of using lazy dot matching with (?:$|;) group after it. NOTE that * quantifier makes the value optional. If it is required, use +.