正则表达式，匹配3组，第二和第三可能是可选的

Question

Given I have a string: Sebastian New York Canal st : Dinner at 5 c'clock. Where:

• Sebastian is first match
• New York Canal st second (might be many spaces and dots)
• Dinner at 5 c'clock. third (might be many spaces and dots)

between 2nd and 3rd group I have colon to separate those groups.

I wrote regular expression: https://regex101.com/r/iI6kN8/1

([A-Za-z0-9]+)?([A-Za-z0-9 ]+)?(:\ ([A-Za-z0-9'. ]+))

And it works when I have 3 groups:

but when I have:

• Sebastian New York Canal st

or

• Sebastian

Does not

Answer 1

Make the 3rd group optional:

([A-Za-z0-9]+)?([A-Za-z0-9 ]+)?(:\ ([A-Za-z0-9'. ]+))?

https://regex101.com/r/zW1oM6/2

Answer 2

Try this regex

/^(\w+)(?:(.+?(?=:|$))\:?(.*)?)/m

See DEMO