How can I make this RegEx into JavaScript RegExp object?

Question

I have this RegEx which allows people to input max 7 digits before decimal and two after which is optional.

I figure it would be neater to put them into a variable. I have searched through with people saying use the RegExp object but I am still confused how it's done.

This is what I have with my RegEx.

/^(\d{1,7})(\.\d{2})?$/

score 2 · Accepted Answer · edited May 23 '17 at 12:24

2

You can use the following code:

var max1 = 7;
var max2 = 2;
var rx = new RegExp("^(\\d{1," + max1 + "})(\\.\\d{" + max2 + "})?$");
console.log(rx.test("1234567.12"));
console.log(rx.test("1234567.123"));
console.log(rx.test("12345678.12"));

Also, check these posts:

edited May 23 '17 at 12:24

Community

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answered Dec 21 '16 at 11:40

Wiktor Stribiżew

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this is nice...never thought of extracting the max numbers out into variables. learned something new again... thx thx – Dora Dec 21 '16 at 12:25

score 0 · Answer 2 · answered Dec 21 '16 at 11:43

0

you can use:

var patt = new RegExp(/^(\d{1,7})(\.\d{2})?$/);

How to test:

console.log(patt.test('1234567ab')) : false

console.log(patt.test('1234567.12')) : true

answered Dec 21 '16 at 11:43

Sahadev

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Ok i got your point just pass limits into variable and append with pattern into RegExp – Sahadev Dec 21 '16 at 12:00

How can I make this RegEx into JavaScript RegExp object?

2 Answers2