how to use rxjs isNumeric() function?

Question

I'm new to rxjs but I think it's part of all ng apps and I've read that it has a handy isNumeric() function. I tried both of the following imports:

import 'rxjs/util/isNumeric';
import 'es6/util/isNumeric';

Here's some sample code that I tried to hook into this rxjs isNumeric() function:

var testString = "100";

//this doesn't compile
var isNumber = isNumeric(testString);

//this fails at runtime
var isNumber = testString.isNumeric();

What am I missing with this?

John Montgomery · Accepted Answer · 2019-09-12T17:16:55.163

10

This isn't specifically a RxJS thing, but more generally how to import standalone functions from other files. There's (at least) two ways you can do this. Since isNumeric only has one function, you can import it this way:

import {isNumeric} from "rxjs/util/isNumeric"
//
var isNumber = isNumeric(testString)

You can also import all the functions in a file at once like this:

import * as rxjsNumeric from "rxjs/util/isNumeric"
//
var isNumber = rxjsNumeric.isNumeric(testString)

But there's not much benefit to that in this particular case.

NOTE: As of RxJS 6, these utility functions are no longer available. However, the syntax still works for the general case of importing functions.

edited Sep 12 '19 at 17:16

answered Oct 02 '17 at 23:56

John Montgomery

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I've noticed that isNumeric("20,000") returns false :( – user2010955 Mar 07 '18 at 10:10
@user2010955 presumably the comma is tripping it up – John Montgomery Mar 07 '18 at 17:33
6

So rxjs 6 doesn't have this? – Post Impatica Aug 29 '18 at 05:12
4

@Helzgate Per [this commit](https://github.com/ReactiveX/RxJS/commit/70058cd), it looks like it was hidden in RxJS 6 because the utils weren't meant to be used externally. – John Montgomery Aug 29 '18 at 19:26
3

in latest version i use it like this: import { isNumeric } from 'rxjs/internal/util/isNumeric' or replace it : https://stackoverflow.com/questions/175739/built-in-way-in-javascript-to-check-if-a-string-is-a-valid-number – mrapi Jul 11 '20 at 09:24
https://github.com/ReactiveX/rxjs/blob/master/src/internal/util/isNumeric.ts For those curious. – Azeroth2b Feb 04 '21 at 15:41

how to use rxjs isNumeric() function?

1 Answers1