Most elegant isNumeric() solution for java

java parsing isnumeric
Doug picture Doug · Aug 17, 2010 · Viewed 38.7k times · Source

I'm porting a small snippet of PHP code to java right now, and I was relying on the function is_numeric($x) to determine if $x is a number or not. There doesn't seem to be an equivalent function in java, and I'm not satisfied with the current solutions I've found so far.

I'm leaning toward the regular expression solution found here: http://rosettacode.org/wiki/Determine_if_a_string_is_numeric

Which method should I use and why?

Answer

Jacob Mattison picture Jacob Mattison · Aug 17, 2010

Note that the PHP isNumeric() function will correctly determine that hex and scientific notation are numbers, which the regex approach you link to will not.

One option, especially if you are already using Apache Commons libraries, is to use NumberUtils.isNumber(), from Commons-Lang. It will handle the same cases that the PHP function will handle.

Related questions

How to parse JSON in Java

I have the following JSON text. How can I parse it to get the values of pageName, pagePic, post_id, etc.? { "pageInfo": { "pageName": "abc", "pagePic": "http://example.com/content.jpg" }, "posts": [ { "post_id": "123456789012_123456789012", "actor_id": "1234567890", "picOfPersonWhoPosted": "http://example.com/photo.…

Read More
How to convert jsonString to JSONObject in Java

I have String variable called jsonString: {"phonetype":"N95","cat":"WP"} Now I want to convert it into JSON Object. I searched more on Google but didn't get any expected answers...

Read More
How to convert/parse from String to char in java?

How do I parse a String value to a char type, in Java? I know how to do it to int and double (for example Integer.parseInt("123")). Is there a class for Strings and Chars?

Read More