Javascript Regular Expression That Matches Two Strings

I don't understand that much regular expression and I want to create one that matches two strings. I know that for one string the code is .match(/something/) and if matches on of t

Solution 1:

To do it with a single regular expression, you'll need to account for the fact that they could come in either order. (.* matches any characters in between the two substrings):

/google.*microsoft|microsoft.*google/

Note: If you wanted to do more than 2 substrings this would get out of hand. 3 strings could come in 6 different orders, 5 strings could come in 120 orders, and 10 substrings could be ordered 3628800 different ways! That's why using features of the language (Javascript) itself, like in Explosion Pills answer, can be much better than trying to do too much with a regular expression.

Solution 2:

The other answers are perfectly fine for your specific problem, but as Paulpro noted really get out of hand when you have more than two words.

The easiest way out is to use multiple checks as Explosion Pills suggests.

But for a more scalable regex-only approach you can use lookaheads:

/^(?=.*google)(?=.*microsoft)(?=.*apple).../

The lookahead doesn't actually consume anything, so after the first condition is checked (that .*google can match), you are back at the beginning of the string and can check the next condition. The pattern only passes if all lookaheads do.

Note that if your input may contain line breaks, .* will not do. You'll have to use [^]* or [\s\S]* instead (same goes for the others' answers).

Solution 3:

You could just use .match twice

str.match(/google/) && str.match(/microsoft/)

In that case it may be faster to use .indexOf

You can also use a verbose regex

.match(/google.*microsoft|microsoft.*google/)