How to concatenate regular expressions in JavaScript?

Question

This is not what I'm asking for:

Is there a way to append a regex into another one (in JavaScript language) ?

The reason for doing so is to simplify code maintenance (e.g. if the included string is long or easier to maintain by a non-programmer).

In Python, for example, i'd write something like:

regstr1 = 'dogs|cats|mice'
regstr_container = '^animal: (cows|sheep|%s|zebra)$' % regstr1
re.compile(regstr_container)

however, in JavaScript, the regular expression is not a string.

re = /^animal: (rami|shmulik|dudu)$/;

or am I missing something?

i've closed this question; but didn't delete it so others that use the keywords i've used will reach this link: stackoverflow.com/questions/185510/… — Berry Tsakala
– Berry Tsakala, Commented Aug 23, 2009 at 15:54

Cᴏʀʏ · Accepted Answer · 2009-08-23 15:44:04Z

6

You don't have to use the literal notation. You could instead create a new RegExp object.

var myRegex = new RegExp("^animal: (rami|shmulik|dudu)$");

answered Aug 23, 2009 at 15:44

Cᴏʀʏ

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1 Comment

+1, and you can make a placeholder: container = "...(cows|sheep|{BLAH}|zebra).."; var re = new Regexp(container.replace("{BLAH}", regstr1);

Eli Grey · Accepted Answer · 2009-08-23 16:39:24Z

3

var regstr1 = 'dogs|cats|mice',
regstr_container = '^animal: (cows|sheep|'+ regstr1 +'|zebra)$',
regex = RegExp(regstr_container);

answered Aug 23, 2009 at 16:39

Eli Grey

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