I have a string, where I need to parse it as a float, but first I need to replace it, if it is not a number (an integer or a float), so I am trying to create an regular expression to do it
My tries results in NaN
One of my best tries is
var $replace = $text.replace(/^[^d.]*/, '');
var $float = parseFloat($replace);
Can anybody tell me, what I am doing wrong?
If you really want to replace everything thats not a digit, then try this:
var $replace = $text.replace(/[^\d.]/g, '');
var $float = parseFloat($replace);
This will replace a string of "123a3d2" with a string of "12332".
$text = 'hello.world'?
$float == NaN. I mean, personally, I would do a validation that this is in fact a number, rather than stripping out characters. But that's not the question the op asked.
/[^\d.]/g allow to put as many . as you want. For example 12.34.5 and 1....2...3..45 works.It looks like you want to strip "non-numeric" characters from the beginning of the string before converting it to float. A naive approach would be:
var s = input.replace(/^[^\d.]+/, '');
var n = parseFloat(s);
This works for inputs like "foo123" but will fail on "foo.bar.123". To parse this we need a more sophisticated regexp:
var s = input.replace(/^(.(?!\d)|\D)+/, '');
var n = parseFloat(s);
Another method is to strip the input char by char until we find a valid float:
function findValidFloat(str) {
for (var i = 0; i < str.length; i++) {
var f = parseFloat(str.substr(i))
if (!isNaN(f))
return f;
}
return NaN;
}
if (! isNaN($text))
$float = parseFloat($text);
else
$float = 0; // or whatever
dor a.from the beginning of your string with nothing... What are you trying to replace/remove exactly?$textmight look like, and what you want$replaceand$floatto look like in those cases?