Make parseFloat convert variables with commas into numbers

Question

I'm trying to get parseFloat to convert a userInput (prompt) into a number.

For example:

var userInput = prompt("A number","5,000") 
function parse_float(number) {
    return parseFloat(number)
}

When userInput = 5,000, parse_Float(userInput) returns 5.

However, if the user was inputting a value to change something else (ie: make a bank deposit or withdrawl) Then I to work properly, parse.Float(userInput) needs to return 5000, not 5. If anyone could tell me how to do this it would help me so much. Thanks in advance.

This may sound stupid, but why don't you get rid of the commas with a simple str.replace ? — Christian Bonato, Nov 30 '14 at 03:50
Careful though, if your app needs i18n, cents ponctuations (decimal marks) differ from country to country : http://www.wikiwand.com/en/Decimal_mark#/Examples_of_use — Christian Bonato, Nov 30 '14 at 03:56
`replace(/,/g, '')`: [Why does javascript replace only first instance when using replace?](http://stackoverflow.com/q/1967119/218196) — Felix Kling, Nov 30 '14 at 04:06
@wyattbergeron1 Yeah that's javascript it replaces the first occurrence only, here is how to do it for all: `"567,763,321".replace(/,/g,"");` — Dimitar Dimitrov, Nov 30 '14 at 04:06
@Bonatoc It's currently a 'game' that i'm working on. It says in the beginning that it will use U.S. standard measurements punctuation etc. — Travis, Nov 30 '14 at 04:12
@wyattbergeron1 Does your program also accept commas in the wrong place? For example, do `5,0,0,0` and `,,,5000,,,` parse as `5000` as well? — Lambda Fairy, Nov 30 '14 at 04:20
@lambdaFairy no, it doesn't Ill figure that out, thanks for pointing it out. — Travis, Nov 30 '14 at 04:22
@DimitarDimitrov That code won't change it if the commas are in the wrong spot. for example, 5,6,7,7,6,3,321 any idea how to fix that? — Travis, Nov 30 '14 at 04:25
It occurred to me that you've only used integers so far, but call `parseFloat`. Do you want to accept decimal points as well? If not, `parseInt` is better. — Lambda Fairy, Nov 30 '14 at 04:47
@LambdaFairy it's set to acccept decimals too, but it automatically accepts them. Only reason I don't use parseInt — Travis, Nov 30 '14 at 14:26

Lambda Fairy · Accepted Answer · 2014-11-30T04:52:46.027

5

Your answer is close, but not quite right.

replace doesn't change the original string; it creates a new one. So you need to create a variable to hold the new string, and call parseFloat on that.

Here's the fixed code:

function parseFloatIgnoreCommas(number) {
    var numberNoCommas = number.replace(/,/g, '');
    return parseFloat(numberNoCommas);
}

I also renamed the function to parseFloatIgnoreCommas, which better describes what it does.

edited Nov 30 '14 at 04:52

answered Nov 30 '14 at 04:29

Lambda Fairy

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Doesn't work, it gives me what js default does, the first instance. If you find a way to fix this, edit this and/or tell me. Thanks! – Travis Nov 30 '14 at 04:49
Whoops, I accidentally tried to parse the original string rather than the new one. The code should work now. – Lambda Fairy Nov 30 '14 at 04:53

score 2 · Answer 2 · answered Jul 23 '15 at 17:46

This is the function I use to scrub my user inputted numbers from a form. It handles anything a user may put in with a number like $ or just accidentally hitting a key.

I copied the following out of an object:

cleanInput : function(userValue){
    //clean the user input and scrub out non numerals
    var cleanValue = parseFloat(userValue.replace(/[^0-9\.]+/g,""));    
    return cleanValue;
},

To make it non-object just change the first line to cleanInput(){....

score 0 · Answer 3 · answered Nov 30 '14 at 04:20

I have put together info from the comments to form a basic answer:

The answer seems to simply be to set parse_float to run :

number.replace(/,/g, "")
return parseFloat(number)

The complete code would look like this:

var userInput = prompt("A number","523,000,321,312,321") 
function parse_float(number) {
    number.replace(/,/g, "")
return parseFloat(number)
}

returns: 523000321312321

Make parseFloat convert variables with commas into numbers

3 Answers3

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