This line "1234567890".contains(s) is brilliant!

Wow!! Absoulately clever!!

About "int arab[];", we're taught in school (at least, I was) that these are "Arabic numerals", but they were really invented by Hindus in India, and brought westward by Islamic traders.

I feel really silly now, this is great.

I don't get a single line XD

Don't be, I am 35 lines ahead :)

Great! Now I feel stupid, lol...

I love this solution :D

Nice one :)
As a little improvements :

• The "number > 99" test is done up to 5 times (one time for each predicate), it can be done outside the stream.
• I'm not of fan of Integer.paseInt(Integer.toString(number)), but I guess it's a compromise for readability to have all the predicates on strings.

Like this one so much!

I dont understand this solution. Can you explain it to me sir? I would like to learn that

i agree with you

How does Stream.<Predicate>of() work? Is it casting the output of the method?

As always, now i feel terrible for my 100 lines solution. Not that I was going for simple, but I do wish I knew more about this functional programming thingy. it's so more concise and easy to read.