How to parse functions names from string using javascript?

Question

I'm looking for a reliable way to get function names from a string. The string values can be something like this:

let str = 'qwe(); asd();zxc()'
//or
let str = 'qwe("foo");asd(1);zxc();' 
//etc.

I want to have an array

['qwe', 'asd', 'zxc']

I tried str.split(';') but how do I get rid of parenthesis and anything they can hold? Is there a regexp that will match all symbols on the left of some other symbol?

What about strings like this? foo(bar(), baz()) Do they need to be covered too? — user1106925
– user1106925, Commented Apr 14, 2017 at 15:29
Would it be possible for the parameters to have strings that could contain something that looks like a function? And are you going to allow for space between the function name and the opening (? — user1106925
– user1106925, Commented Apr 14, 2017 at 15:36
@Andrey It sounds like you're going to need to write a parser. Regular expressions cannot count nested parentheses. — Mike Cluck
– Mike Cluck, Commented Apr 14, 2017 at 15:41

Mohammad · Accepted Answer · 2017-04-14 15:29:05Z

1

You can use this simple regex to find function names in .match()

var str = "qwe(); asd();zxc()";
console.log(str.match(/\w+(?=\()/g));

answered Apr 14, 2017 at 15:29

Mohammad

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3 Comments

Mike Cluck Over a year ago

This will give the wrong result if the function calls contain any identifiers in their argument list.

artemean Over a year ago

Thanks, that's very close. What about this: var str = "qwe(); asd();zxc ()";?

Mohammad Over a year ago

@Andrey Your example hasn't such function. However use \w+\s*(?=\()

Manuel Morales · Accepted Answer · 2017-04-14 15:32:53Z

0

The first case it's fairly simple with regex a simple

[A-Za-z]\w+

would suffice.

on the second case it's a little bit trickier but maybe supressing the match for this

"(.*?)"

maybe a possibility

answered Apr 14, 2017 at 15:32

Manuel Morales

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