Javascript match anything until pattern

Given example-123, I need to extract just example. Also example could be: example-example-345, in which case I need example-example. This is the pattern I'm looking for:

> str.match('-[0-9]{1,}$')[0]
'-123'

I tried:

str.match(/(.*)-[0-9]{1,}$/)
'example-123'

and

str.match(/(?s).*)-[0-9]{1,}$/)[0]
Uncaught SyntaxError: Invalid regular expression: /(?s).*)-[0-9]{1,}$/: Invalid group

and

str.match('[^-[0-9]{1,}$]')
null

and

str.match('(.*)[^-[0-9]{1,}$]')
null

and

str.match('/.*/[^-[0-9]{1,}$]')
null

and

str.match('.*^(-[0-9]{1,}$)')
null

... the list goes on

You can use a positive lookahead for that:

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

let str = 'example-example-123';
console.log(str.match(/.+(?=-123)/)[0]);

str = "example-123";
console.log(str.match(/.+(?=-123)/)[0]);

str = "example-example-example-123-something-after";
console.log(str.match(/.+(?=-123)/)[0]);

<!-- end snippet -->

Try this:

str.match(/^(.+)-\d+$/)[1]

matching everything till a hyphen followed by numbers!

And with [1] it will get the first part only!

You can use *? matches the previous token between zero and unlimited times, as few times as possible, expanding as needed (lazy, none greedy match)

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

const str = 'example-example-123';

console.log(str.match(/(.*?)-\d/)[1]);

<!-- end snippet -->

You can match the regular expression

^([a-z]+)(?:-)*(?=-)

Demo

I have assumed the word preceding the first hyphen must contain only lowercase letters. That assumption may be faulty, of course, in which case ([a-z]+) would have to be changed accordingly. To match a letter followed by zero or more letters and numbers, for example, it would be ([a-zA-Z][a-zA-Z0-9]*).

As shown at the link, the text indicated below by the party hats was matched.

example-123
^^^^^^^

example-example-345
^^^^^^^^^^^^^^^

dog-dog-dog-123
^^^^^^^^^^^

dog-dog-cat-123
^^^^^^^

dog-cat-cat 123
^^^^^^^^^^^

dog-dog123
^^^

dog

There is no match in the last example.

The regular expression can be broken down as follows.

^         Match beginning of the string
(         Begin capture group 1
  [a-z]+  Match one or more lowercase letters
)         End capture group 1
(?:       Begin non-capture group
  -     Match a hyphen followed by the contents of capture group 1
)*        End the non-capture group and execute it zero or more times
(?=       Begin a positive lookahead
  -       Match a hyphen
)         End the positive lookahead

Note that the positive lookahead (?=-) forces the match to be followed by a hyphen but that hyphen is not part of the match that is returned.