Regular expression for "1.0"

[shukla raghav]

i ahve written a small set of statements to identify decimal numerals, i think the code is fine but its not working..

  String s = "1.0";
    System.out.println(s.matches("\\d(\\.)"));  

whats wrong with the code ? why is it not working? what will be the correct regex expression of identifying fractional values ?

[Praveen Rajendran]

Hi Shukla,

I guess the reason why this wud would have given you false back is because the regex defined by you does not match any character beyond the decimal.

ie it wud would have returned true if your string was "1." and not 1.0"

The below regex wud would work to match 1 or 2 decimal places.

System.out.println(s.matches("\\d+(\\.[0-9]{1,2})"));

Let me know if it helps.

[Campbell Ritchie]

Please be careful about spellings: it's not "wud" but "would".

[Praveen Rajendran]

Hi Campbell,

Apologies for the short words . Thanks for bringing to attention . Corrected the same with a strike through.

I am new to replying posts in Javaranch. Till date was only reading it. Thought of putting some time to help other to the way I can. Will take care going forward about spellings

[Campbell Ritchie]

Apologies accepted

[shukla raghav]

well praveen, i got the answer for the same long back. In s.matches("\\d(\\.)") the regex expression applies to the entire string, i mean if the string was str = 2. or 654. then this expression would have worked out.But for a string like 2.34 the correct regex would be "\\d\\.\\d+" now it will work.

Anyways thanks for your effort.