Regex check first character

Question

I want to use a regex first character is equal 5 and other string must be number. For example 5046834578 or 5789825364. I used a pattern for to check all string is number but it is not enough to check. How can I do?

var pattern=[0,9];

That's very basic regex use, please follow a quick tutorial on regex, you'll learn much more from it. — Aaron, Sep 03 '18 at 10:32

score 3 · Accepted Answer · edited Sep 03 '18 at 10:46

3

Here's the regex you need:

/^5\d+$/

Anything in / pairs are resolve as regex.

^ means it must starts with the following rule.
5 means 5.
\d means any digit.
+ means previous rule repeat 1 or more than 1 time.
$ means it must ends with the previous rule.

Here's the full code:

var regex = /^5\d+?$/;
var tester = '556464622';
var result = regex.test(tester); // true

edited Sep 03 '18 at 10:46

Paolo

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answered Sep 03 '18 at 10:43

Hao Wu

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The way you explained every single character is really applaudable. Thanks. – Mukesh Kumar Sep 23 '20 at 15:27

Regex check first character

1 Answers1