Angular regex error - regex

Question

I'm creating a form in Angular that requires the rate field to take only numbers with 2 decimal places. My HTML is as follows:
<input type="number" class="form-control" (keypress)="_keyPress($event)" (ngModelChange)="Valuechange($event,salesorder,'Rate')" [ngModelOptions]="{standalone: true}" name="customerCode" #customerCode="ngModel" [(ngModel)]="salesorder._dto.rate" [style]="{'text-align':'right'}" />
On every keypress event I'm calling _keyPress() method as follows:
_keyPress(event: any) {
const pattern = /[0-9\+\.\ ]/;
let inputChar = String.fromCharCode(event.charCode);
if (!pattern.test(inputChar)) {
// invalid character, prevent input
event.preventDefault();
}
}
The above regex works fine but does not restrict the number to 2 decimal places. I tried with various regex but could not implement the restriction to 2 decimal places. The last regex I used to do the same is as follows:
const pattern = /[0-9]+(.[0-9]{0,2})/;
I have no much idea about regex.

Answer 1

You can try following regex:
const pattern = /^[0-9]*\.[0-9]{2}$/
Or you may use shorthand character class \d instead of [0-9] i.e:
const pattern = /^\d*\.\d{2}$/
Description:
[0-9]{2}$ or \d{2}$ will make sure that there are exactly 2 numbers after decimal point.
You may replace * with + if there must be at least one number before point.

Answer 2

To restrict the decimal place to 2 digits, you could use {2}.
{0,2} means match zero, one or two times.
[0-9]+(\.[0-9]{2})
Note
This uses an unnecessary capturing group (\.[0-9]{2}) which could be written as \.[0-9]{2}
You could also use anchors to match from the beginning ^ to the end $:
^[0-9]+(\.[0-9]{2})$
or
^[0-9]+\.[0-9]{2}$
var pattern = /^[0-9]+(\.[0-9]{2})$/;
var inputs = [
"22.65",
"22.6",
"22.656"
];
for (var i = 0; i< inputs.length; i++) {
console.log(pattern.test(inputs[i]))
}