I am adding a validation on a text box for decimal number (4,2). i tried below code, it works after the decimal point (meaning it's restricting user inputing more than 2 digits after decimal point) but it doesn't restrict user inputing more than 4 digits before the decimal point.
ng-pattern-restrict="^[0-9]{0,4}+(.[0-9]{0,2})?$"
The {0,4} means "0 to 4 of the proceeding pattern". The + means "one or more of the proceeding pattern" and the . means "any character".
So it sounds like you need to drop the + (you already have the count specified in {0,4}) and escape the . to match the literal decimal point.
^[0-9]{0,4}(\.[0-9]{0,2})?$
Keep in mind this is not a universally acceptable method of validating decimals. Different regions use different symbols for the decimal point, for example.
+ mean possessive here. However no idea if modern JS supports those
[] means match any of the enclosed character sets, so you can just put a comma next to 0-9. But that doesn't solve your longer number problem. Try out some regex and ask another question if you get stuck.