I have an user input where user can edit price of something. To leave data consistance I would like to manipulate with that string on front-end site.
What I want to do is:
1234 to 1234.00
12.3 to 12.30
12,3 to 12.30
1234.45 to 1234.45
So basicly,
Replace comma with dots
this should be done easy with somehing like:
str.replace(',', '.');
Add dots if number if not decimal and also always change number of digits on two(so add 0 if needed)
I try to do something like:
priceByUser = priceByUser.replace(/^\d*\.?\d*$/, "$1\.00");
unfortunately this really doesnt even work as I expected.
Is there a chance someone can help me to solve this issue?
Thanks
You could consider using a regular expression to replace your commas and periods with just decimal points and then parse the values as floats via parseFloat() then finally, use the toFixed(2) function to indicate that you want two decimal places :
// This will clean up your input (consolidating periods and commas), parse the result
// as a floating point number and then format that number to two decimal places
priceByUser = parseFloat(priceByUser.replace(/,/g,'.')).toFixed(2);
If you wanted an extra-level of validation, you could consider stripping out any non-digit or decimal places after this occurs :
// Sanitize
priceByUser = priceByUser.replace(/,/g,'.').replace(/[^\d\.]/g,'');
// Parse and format
priceByUser = Number(priceByUser).toFixed(2);
Example
You can see a working example here and and example of input/output below :
Related
I am facing issues with regex pattern for Float number -> that should not end or stars with decimal points..
I have tried following regex patter.. that is
regex = /^\d*\.?\d*$/
// on doing
regex.test(11.)
regex.test(.11)
// it is returning true in checking
// I need to make this as false, comment will be much helpful
thank you.
You should bear in mind that regex only works with strings. When you pass a non-string variable as input to a RegExp, it will first coerce it to a string type.
Have a look:
console.log(11. , 'and', .11); // => 11 and 0.11
So, the actual string values you pass to your ^\d*\.?\d*$ regex are 11 and 0.11 that can be matched with the given pattern. Actually, ^\d*\.?\d*$ is a regex that is usually used for a very loose live number input validation, e.g. see How to make proper Input validation with regex?.
What you want is to implement a final, on-submit validation pattern, so that it could not pass strings like 11. and .11. There have been lots of threads discussing this kind of regex:
Regular expression for floating point numbers
regular expression for finding decimal/float numbers?
Basically, for validation, you will need something like
/^\d+(?:\.\d+)?$/.test(input_string)
/^[0-9]+(?:\.[0-9]+)?$/.test(input_string)
/^[0-9]+(?:\.[0-9]{1,2})?$/.test(input_string) // Some need to only allow 1 or 2 fractional digits
/^[0-9]{1,3}(?:\.[0-9]{2})?$/.test(input_string) // 1-3 digits in the integer part and two required in the fractional part
I have following number with e+ on it
9.074701047887939e+304
I want to take only 9.07
So I tried below , but its not working , its returning full output
console.log(parseFloat(9.074701047887939e+304).toFixed(2));
Ps : I also need the code to work for normal numbers aswell for example 892.0747010 , should output 892.07
toFixed trims digits after the decimal point, but your actual number is very large - it doesn't have a decimal point.
If you don't know in advance whether the number is large or not, one option is to call toFixed(2) on the number first (trimming off and properly rounding digits past the decimal point for small numbers), then using a regular expression to take the numeric part only (removing the e if it exists), then call toFixed(2) again (trimming off and properly rounding digits past the decimal point for large numbers):
const fix = num => Number(
num.toFixed(2).match(/\d+(?:\.\d+)?/)[0]
).toFixed(2);
console.log(fix(9.074701047887939e+304));
console.log(fix(123.4567));
console.log(fix(12345));
Since you mentioned for both 9.074701047887939e+304 and 9.074701047887939, you want the answer to be 9.07.
For 9.074701047887939e-304 I assume you want 9.07 too, although you might actually want 0.00.
const twoDecimal = (a =>
(a.toString().match(/e/) ? Number(a.toString().match(/[^e]*/)[0]) : a).toFixed(2)
);
console.log(twoDecimal(9.074701047887939e+304));
console.log(twoDecimal(9.074701047887939e-304));
console.log(twoDecimal(9.074701047887939));
console.log(twoDecimal(789.074701047887939));
console.log(twoDecimal(0.00001));
console.log(twoDecimal(0.20001));
console.log(twoDecimal(-9.074701047887939e+304));
console.log(twoDecimal(-9.074701047887939e-304));
console.log(twoDecimal(-9.074701047887939));
console.log(twoDecimal(-789.074701047887939));
console.log(twoDecimal(-0.00001));
console.log(twoDecimal(-0.20001));
console.log(twoDecimal(0));
Im designing a conversion website where i perform calculations on inputted numbers and i need my input or textarea to receive and interpret numbers entered in different fashions
like:
Entry = 3,000,000.1111
Interpreted value = 3000000.1111
or
Entry = 3000000.1111
Interpreted value = 3000000.1111
and I want to include a second input for European decimal notation
(or if possible have the same input do both)
Entry = 3.000.000,1111 (comma acts a decimal, decimal as separator)
Interpreted value = 3000000.1111
I wonder how I could do this. I suspect from some of my research that I could use regex.
Also should i use an input or a textarea? I want to limit the size of the number to 40 places.
It seems the textarea Im currently using won't recognize any values after a comma when a comma is used. I realized this is due to parseFloat. So I need to remove the commas using .replace() before parsing. But what do I do in the instance of European notation where the comma IS the decimal point? I suspect I should use regex to identify if a number is in comma decimal notation or standard decimal point notation and then outline the appropriate replacement behavior based on that. Any ideas how to write regex to identify a number between .0000000001 and 1,000,000,000,000,000 by only the separator and decimal point? What about when the entry doesn't use either? 12000 for example. Any help with this would be appreciated. Using HTML5 and Javascript. I am not using a form and am new at this. This is my first web page so please be patient with my questions.
I was thinking about this:
input = //value from textarea as a string
if(/REGEX which determines that the structure of the number is N,NNN.NN/.test(input)){
input = input.replace(/\,/,""); //replace the commas with nothing
}
else if(/REGEX which determine that structure of the number is N.NNN,NN/.test(input){
input = input.replace(/\./,""); //replace the decimal point separators with nothing
input = input.replace(/\,/,".");//replace the comma decimal with a point decimal
}
else{
//input unchanged assuming is NNNN without decimal
}
number = parseFloat(input);
I want to keep the possibility open for them to enter large numbers and also to use numbers less than one to 10 decimal places. Thanks to those who contributed.
Best,RP
I believe this should handle everything:
^[1-9](?:\d{0,2}(?:([,.])\d{3})*|\d+)(?:(?!\1)[,.]\d+)?$
You're treading on complicated territory here. Also, the above RegEx does not allow for values less than "1".
Basically, the RegEx does the following:
Allows for no thousandths separators ("," or ".") but ensures if they are used that they occur in the correct places.
Allows for either "," or "." to be used as both thousandths/cents separators, but ensures that the cents separator is not the same as the thousandths separator.
Requires the string equivalent number to begin with any digit other than "0".
To implement this you could attach an event listener to your form element(s) and use JS to do a simple .test.
After reading further, I think I misinterpreted your goal originally. I assumed you simply wanted to validate these values with a RegEx. I also assumed you're trying to work with currency (ie. two decimal places). However, fret not! You can still utilize my original answer if you really want.
You mentioned input and textarea which are both form elements. You can attach a listener to these element(s) looking for the input, change, and/or keyup events. As a part of the callback you can run the .test method or some other functionality. Personally, I would rethink how you want to handle input. Also, what's your actual goal here? Do you really need to know the thousandths separator or keep track of it? Why not just disallow any characters other than the one decimal point/comma and digits?
Also, parsing numbers like .0000000001 as a float is a terrible idea. You will lose precision very quickly if you do any sort of calculations such as multiplication, division, power, etc. You're going to have to figure out a different method to do this like storing the number to the right separately and as integers instead then go from there.
I can help you if you describe what you're trying to do in better detail.
I have the problem that when i round a number to 2 decimals the parseFloat() function removes .00 from the number. I have tried
var num = parseFloat(Math.round(19 * 100) / 100).toFixed(2);
The return: num="19.00"
The return i need: num = 19.00
I know 19 = 19.00, but i am using a service that always require two decimals .00
The function returns a string with the right value. When i parse it to float the .00 is removed.
You cannot get 19.00 as float, only as string, because numbers always remove trailing zeros.
Maybe you can show us a bit more code to get an idea, there you need these trailing zeros?
Numbers do and can not hold information about their representation. They are only a numerical value.
When you display a number using window.alert, console.log or similar, you are not looking at a number, but at a string. Those display functions convert numbers to strings before displaying them. Number.toFixed also converts numbers into strings, with the difference being that it rounds them to two decimal places, so you end up with another representation of the same number.
What I am trying to say is that to display a number, you cannot get around converting it to a string. Whether you do it explicitly or the display function does it for you. When you send the number to the service that you are using, you are probably also sending a string (JSON, XML, etc. are always strings once you send them). If you need the value of the number for calculations, use it, then convert it in the end. No matter how, you have to do it in the end if you want those 0's at the end.
I have read some thousand comma separator JavaScript question/answer but found it hard to apply it in practice. For example I have the variable
x = 10023871234981029898198264897123897.231241235
How will I separate it in thousands with commas? I want a function that not only works with that number of digits but more. Regardless of the number of digits the function I need has to separate the number in commas and leaving the digits after the decimal point as it is, Can anyone help? It has to work on number and turn it into string.
First of all, for such huge numbers you should use string format:
var x = "10023871234981029898198264897123897.231241235";
Otherwise, JavaScript will automatically convert it to exponential notation, i.e. 1.002387123498103e+34.
Then, according to the question about money formatting, you can use the following code:
x.replace(/(\d)(?=(\d{3})+\.)/g, "$1,");
It will result in: "10,023,871,234,981,029,898,198,264,897,123,897.231241235".