It used to be really popular, particularly in the late 1980s and 1990s. A really good language for learning object‑orientation (OO). Bertrand Meyer plugged it as a reliable language; it has keywords which cause Exceptions to be thrown if a class invariant is breached, or a loop variant doesn’t alter, etc. It is fully OO, even things like INTEGER being full‑blown objects. Unfortunately it has a context‑sensitive grammar, and about 2005 there were major changes to the language specification and many of its supporters deserted it. If you look at old Tiobe indices, you can watch it fall gradually from 15th position to the limbo of “not graded because the differences are too slight” in the >50 category.
check the unicode(or ascii, i'm not sure which, but i think its unicode) of each character, to see if it falls in the range 48-57.
this can be done by
}if the counter=string.length(), its a number, as each character is a number
I hope this helps!
Mike Simmons wrote:In comparison, Character.isDigit() simply works.
And not only does it Just Work, it works better because it identifies "٢" as a digit. It doesn't restrict itself to just Latin digits, in other words.
(In case you don't recognize that character, it's the Arabic digit 2.)
imed joseph wrote: you can use regular expression.[0-9]
String str = "98989896";
Pattern pattern = Pattern.compile("[0-9]");
Matcher matcher = pattern.matcher(str);
I believe your regex will not work. A few weeks ago I posted something for finding whether a String was all letters, and you can use that with slight changes to find whether your String is all numeric. Of course, some Strings containing all digits probably don't fulfil people's usualy concept of a number, and hegative numbers fractions will not be found like that.
This is probably not a usual format for a number, but will be found by the technique with a Stream: "00000000000000000000000".
Bob Robertson wrote:Hello,
I have a situation where I want to validate whether the value passed in as a String() is a numeric v. alpha/special char value. The process that will consume this data post-validation will be expecting numeric values.
Can someone give me a hint with how to do this without using a NumberFormatException? If the Exception is encountered the only recovery necessary will be to log the data that needs to be reviewed since the data is subjective and cannot be modified at runtime based on any conditions. I could just try to catch a NFE when trying to convert the value to an integer and then log that that data needs to be eye-balled, but I was hoping to do something a little more purdy.
If I were to use the java regex uitils, would I be provided a means to eliminate all alpha and special characters?
Just looking for a thums-up/thumbs-down or a possible alternative.
!(c < '0' && c > '9').
Let's have a look at how you might do it with a Stream:-This ’ is \u2019.
You can get an IntStream from a String with its chars() method (actually inherited from CharSequence). That Stream goes through each char as if cast to an int. You can use its allMatch() method which will stop execution whenever it hits a false. Note the indentation: the .s align vertically.
The IntPredicate required by allMatch is replaced by a λ expression, in this case testing whether the int called i is in the range 0...9.
Your technique will match the following text:-
and won't match
I would still preferorRemember that a Scanner has these three methods: 1 2 3.
I am pretty sure some of this has been discussed earlier in the thread or here.
It all goes to show how useful old threads can be,