Level 75
May 31, 2024
7
Level 3
Format numbers with scientific notation
I receive numbers in scientific notation formats. Then I create trailing zeros with toFixed(), but it converts the return to a string, but I need them as a number. If I use Number(), it reverts to scientific notation.
Look:
if (dataPoint[1].toString().includes('e')) {
var casas = dataPoint[1].toFixed(16).split(".")[1].match(/^[0]+([1-9])/)[0].length;
yValue = parseFloat(dataPoint[1]).toFixed(casas);
} else {
yValue = dataPoint[1];
}
How do I get decimals in number format using toFixed()?
Level 3
@jlrdw I ended up getting a little more confused... all options convert to string. I couldn't solve my problem with your help
Level 75
@mvnobrega you display a string.
Level 80
How do I get decimals in number format using toFixed()?
@mvnobrega I think you’re misunderstanding numbers and strings.
If you have this value:
var value = 1000.5;
And then call toFixed(2) on it then yes, it’s going to return a string, with that many numbers after the decimal point. The MDN docs do say this in the documented return type for the toFixed method: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/toFixed#return_value
The reason being, any trailing zeroes on a number are just superfluous in floating point numbers. 1000.500 is the same as 1000.5. You can test and verify this with the following code:
var value = 1000.500;
console.log(value); // 1000.5
1 like
Level 3
@martinbean but I receive this as a value: 1.38e-11 , it appears as a number type and I need to treat it as a number even after toFixed(). It seems so simple, but I can't solve it
Level 75
@mvnobrega for display use the string. To calculate if needed convert to numbers first.
NOTE: Messing with floats, you loose precision.
I prefer using php or python for numbers, in php you can use: https://www.php.net/manual/en/function.number-format.php
I have always resolved this stuff with a little "trial and error".
1 like
Level 80
@mvnobrega Please re-read my post. I described in detail. The toFixed method returns a string. Not a number.
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