Use of substr in javascript

Question

var MDI = '39.741679085941385';
var revMDI = "";

I am needing to modify the MDI value by removing the "." and all characters to the right of it.

I've tried this code and I'm getting a mozilla error:

var revMDI = MDI.substr(MDI,0,indexOf(MDI,'.'));

The error I'm getting is:

org.mozilla.javascript.EcmaError: TypeError: Cannot find function substr.

Any help/direction would be appreciated. Thanks.

The first argument to substr() should be 0, not MDI.

Barmar
– Barmar

2014-06-23 20:10:53 +00:00
Commented Jun 23, 2014 at 20:10 — Barmar
– Barmar, Commented Jun 23, 2014 at 20:10

Scimonster · Accepted Answer · 2014-06-23 20:07:35Z

4

In other words, get the integer value.

var revMDI = parseInt(MDI);

answered Jun 23, 2014 at 20:07

Scimonster

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Comments

dpk2442 · Accepted Answer · 2014-06-23 20:08:42Z

2

You need to use MDI.substring(0,MDI.indexOf('.'));.

See the MDN Docs for substring and indexOf.

answered Jun 23, 2014 at 20:08

dpk2442

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2 Comments

Barmar Over a year ago

Why would the error say substr if the problem is with indexOf?

dpk2442 Over a year ago

Sorry, I noticed the second problem first. I edited my answer to include both.

Oriol · Accepted Answer · 2014-06-23 20:21:43Z

1

You can do it with just two characters:

var revMDI = MDI | 0;

The bitwise OR operator | coerces MDI to a number and truncates it to 39. And then the bitwise OR with 0 is the identity.

edited Jun 23, 2014 at 20:21

answered Jun 23, 2014 at 20:15

Oriol

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Comments

Elliott Frisch · Accepted Answer · 2014-06-23 20:12:27Z

0

You could do it indexOf('.'),

var MDI = '39.741679085941385';
var revMDI = MDI.substr(0, MDI.indexOf('.'));

jsFiddle

answered Jun 23, 2014 at 20:12

Elliott Frisch

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3 Comments

Melinda Over a year ago

Thanks for all the replies. Unfortunately, I'm getting the same error. I'm working in an IDE called Provenir and it apparently is pretty picky. Thanks.

Elliott Frisch Over a year ago

@Melinda Did you try the fiddle?

Melinda Over a year ago

This is actually not going through the browser but through the Provenir IDE, would that matter?

durbnpoisn · Accepted Answer · 2014-06-23 20:16:58Z

0

Your syntax is wrong:

revMDI = MDI.substr(0, MDI.indexOf('.'));

You have to declare the string you wish to modify with substr AND then with indexOf.

The way you were doing it kinda made no sense.

answered Jun 23, 2014 at 20:16

durbnpoisn

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Comments

Community · Accepted Answer · 2017-05-23 12:05:43Z

0

The correct syntax is:

var revMDI = MDI.substr(0, MDI.indexOf('.'));

But I would prefer Scimonster's answer more.

edited May 23, 2017 at 12:05

CommunityBot

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answered Jun 23, 2014 at 20:11

Orel Eraki

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