New classifications of numbers introduce new numbering systems – premium-rate, local-rate, toll-free, and so on.
When a carrier runs out of one set of numbers – like, sadly, premium-rate – they simply introduce a new prefix.
Some changes have enormous implications; in the United Kingdom some years ago, for example, the entire regional numbering system underwent a drastic change, with virtually every area code getting an additional “1” inserted.
Even then, the capital had a subtly different system.
When you’re collecting data from users, there are two key challenges; collecting that information, and validating it. In this article I’ll discuss some of the challenges around collecting, validating, and displaying telephone numbers.
Some types of information are straightforward – someone’s age, for example, couldn’t really be simpler to collect and to validate. Perhaps you’re thinking that since telephone numbers tend to follow a pretty rigid format, such as this: So based on that, we know that the regular expression apparoach isn’t as simple as we first thought – but that’s only the half of it. Sure, if you know that the number you’re collecting is going to be for a specific country, you may be able to use a regular expression. Let’s look at some of the other issues around telephone numbers, and why they make our job even harder.
When the user presses Enter, than java Script checks that phone number is valid or not.
If the number is valid then alert message will be displayed as ‘Phone number is valid’.
Here is an excerpt from As you can see, this demonstrates that Austria uses the international dialing code 43. Well, using the magic of Lodash (or Underscore), there are a few ways in which we can query dialing code-related information.
A regular expression can easily check whether a user entered something that looks like a valid phone number.
Regular expressions are patterns used to match character combinations in strings.
There isn’t necessarily a one-to-one mapping; 44 for example, is used not just for the United Kingdom but for the Isle of Man, Guernsey and Jersey.
Numbers must also be altered according to where you’re dialing from.