Question

is php useful to learn?

Answer 1

It depends on what you want to do.

Answer 2

PHP is meant to be a server-side language for websites. And it is extremely popular for that:
http://w3techs.com/technologies/overview/programming_language/all

You can see that about 80% of the websites using a server-side language work with PHP.
Even if this data is a bit off (although it claims to be up to date) the big picture is clearly in favor of PHP.

Now, all this doesn't mean PHP is the 'the best', it just means that de facto it is a standard language for server-side web development.
I'd say the reason is PHP being powerful and yet relatively easier to work with. The set up is not complex, the learning curve is fast and it comes with pretty much everything you need (and there are many extensions).

Because PHP is used only as the server-side web development language, it means that web developers also have to know many other things like client-side web development, which is typically HTML + CSS + Javascript (and also libraries like JQuery for example), and working with web-servers (like Apache), protocols (like HTTP, FTP), databases (Mysql for example) and more.
New web-developers have various of new subjects to learn so picking simpler tools is only natural.

However, simplicity is not everything.
PHP is relatively slow compared to other languages. (although for small-medium websites it shouldn't be a problem)
When it comes to the language itself, there is a favor towards other languages, like python for example.
Ruby on rails got a reputation of a more robust and organized environment for server-side web development. But it is not as simple and for beginners, that have many other subjects to learn, it might be too much to swallow all at once.

If you are not familiar with web development at all than I'd recommend going with PHP. (although you should begin with client-side first)
if you are then I'd consider Ruby on rails instead.

Hope it helps \( \Large ☺\)

Answer 3

If you are focusing on web development, PHP is one of the top choices. While some say it is slow, there are others that argue against that. They have some pretty impressive results to support their position.

If you are focusing on anything other than web development, it is not a good choice.

This sort of trade off is why a lot of people pick up Java at some point. Java is generally not the best solution for anything. However, it has extension that make it very good at just about everything. So even if it is not your primary programming language, it is a good 2nd or 3rd.

On and on, every language gas some tradeoff like that. So the real question becomes: what type of programming will you be doing?