Filter array based on regex

Asked Mar 17 '18 at 12:55

Active Mar 17 '18 at 12:55

Viewed 29 times

I have following array:

array = ['S2A_MSIL1C_20180213T041901_N0206_R090_T46QCH_20180213T075744.SAFE','S2B_MSIL1C_20180208T041929_N0206_R090_T46QCJ_20180208T075342.SAFE','S2A_MSIL1C_20180213T041901_N0206_R090_T46QCJ_20180213T075744.SAFE','S2B_MSIL1C_20180310T041559_N0206_R090_T46QDK_20180310T075716.SAFE']

I filter this array using this regex:

regex = new RegExp('(T46QCJ|s)','g');

and apply it on the array like

var filter = array.filter(e => regex.test(e));

The output is

["S2B_MSIL1C_20180208T041929_N0206_R090_T46QCJ_20180208T075342.SAFE"]

instead of the desired result

['S2B_MSIL1C_20180208T041929_N0206_R090_T46QCJ_20180208T075342.SAFE','S2A_MSIL1C_20180213T041901_N0206_R090_T46QCJ_20180213T075744.SAFE']

Why is the second match not inserted?

asked Mar 17 '18 at 12:55

dwalin93

2

Get rid of the "g" flag. That's the problem. I don't know why but the "g" flag has some sort of mystique. – Pointy Mar 17 '18 at 13:02
Thanks and sorry for the dublicate question. – dwalin93 Mar 17 '18 at 13:04
See https://jsfiddle.net/9c8ewd5b/2/. No mystique, it just advances the regex index upon a valid match. – Wiktor Stribiżew Mar 17 '18 at 13:04
For me its working perfectly fine with regex /(T46QCJ|s)/g – binariedMe Mar 17 '18 at 13:04
@WiktorStribiżew right I know what it does, but what I don't know is what makes it so unnecessarily popular :) – Pointy Mar 17 '18 at 13:04
@binariedMe if you put that regex **literal** in the `.filter()` callback the code works because that regex is brand new on each call to the callback. – Pointy Mar 17 '18 at 13:05
Oh, that's news to me. Great to know that. @Pointy Thanks – binariedMe Mar 17 '18 at 13:06

Filter array based on regex

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