I want to allow user to input decimal value with maximim 9 integer digits, and maximum 2 decimals after dot. But also this value can be negative, with "-" sign. Evereything is ok, except this minus sign. Though sites like "regexp.online" show that my regular expression is fine, it does no work in js+jquery. Minus sign fails the checking. See:
$('[name="price"]').bind("change keyup input", function() {
pricecheck = '^(\\-)?\\d{1,9}(\\.\\d{0,2})?$';
var regex = new RegExp(pricecheck, 'g');
if (!regex.test(this.value)) {
console.log('not in regex');
this.value = this.value.slice(0, -1);
}
});<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input name="price" style="height:20px;">And fiddle - https://jsfiddle.net/obc6qptf/
I tried this "minus" without backslashes - the same result. What is wrong?
You need to use a regex that will match the first digit optionally:
const regex = /^-?\d{0,9}(?:\b\.\d{0,2})?$/;
Note the \b word boundary is used to make sure the . separator does not come right after -, and if you need that, remove \b from the pattern.
Details:
^ - start of string-? - a - char (optional)\d{0,9} - zero to nine digits(?:\b\.\d{0,2})? - an optional sequence of
\b - a word boundary to require a digit (here) before .\. - a dot\d{0,2} - zero, one or two digits$ - end of string.See the JavaScript demo:
$('[name="price"]').bind("change keyup input", function() {
const regex = /^-?\d{0,9}(?:\b\.\d{0,2})?$/;
if (!regex.test(this.value)) {
this.value = this.value.slice(0, -1);
}
});<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input name="price" style="height:20px;">