Issue with REGEX in javascript

Question

I get an issue using REGEX, it is probably about my REGEX but I need some helps.

I need to match all string containing "D"...

Test string 1 : D
Test string 2 : aaaaaaDqqqqq
Test string 3 : Dssssssss
Test string 4 : D4564646
Test string 5 : 1321313D2312
Test string 6 : ppppprrrrrr

My regex :

/^.+D.+|(:?^|\s)D$/gi

It works only for 1 and 2 and it should works for 1, 2, 3, 4 and 5.

Maybe [`^.*D.*$`](https://regex101.com/r/L63Meu/1)? Or `[^D]*D[\s\S]*`. — Wiktor Stribiżew, Aug 29 '18 at 13:40
However, it seems you may just use `indexOf` or `includes`, which is a more natural way to check if a char exists in an input string in JavaScript. — Wiktor Stribiżew, Aug 29 '18 at 13:45

score 0 · Answer 1 · answered Aug 29 '18 at 13:46

0

In your case problem is with + operator which is literally Matches between one and unlimited times so it wont work if letter "D" will be in the beggining or the end of string. Try this regex: ^.*D.*$ with asterix, as it is defined as Matches between zero and unlimited times

See example

answered Aug 29 '18 at 13:46

Jacek Rosłan

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1

`^.*D.*$` is inefficient and will choke on multiline input. Do not use it. – Wiktor Stribiżew Aug 29 '18 at 13:47

score 0 · Answer 2 · answered Aug 29 '18 at 13:46

0

Following regex should work for you

.*D.*

answered Aug 29 '18 at 13:46

Rakesh

4,004
2
19
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1

`.*D.*` is inefficient and will choke on multiline input. Do not use it. – Wiktor Stribiżew Aug 29 '18 at 13:47

score 0 · Answer 3 · answered Aug 29 '18 at 13:50

0

If all you need to do is test for whether or not a string contains a D character, it's just /D/

var tests = [
"D",
"aaaaaaDqqqqq",
"Dssssssss",
"D4564646",
"1321313D2312",
"ppppprrrrrr"
]

tests.forEach(str => console.log(/D/.test(str)))

answered Aug 29 '18 at 13:50

jmcgriz

2,819
1
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executable · Answer 4 · 2018-12-12T13:49:02.867

-1

Instead of using a regex simply use the includes function

var string = "aaaaaaDqqqqq",
substring = "D";
if(string.includes(substring)){
    console.log("contain")
}else{
    console.log("don't contain")
}

edited Dec 12 '18 at 13:49

answered Aug 29 '18 at 13:42

executable

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Issue with REGEX in javascript

4 Answers4