CODEWITHSUNDEEP
javascriptregexvalidation
Jatinder Sharma
Jatinder Sharma

Reputation: 287

Validating numeric value in text field does not give desired result

Validating a text field value which may be positive whole number or number with one decimal point and one decimal after the point in javascript:

123
1
12345
233.2
1212.2
1.1

are valid numbers and 

1.222
1.33
-89789
-3

are invalid numbers.

Ihave applied this but not get desired result

  function CheckOneDecimal(txtbox) {
             if (txtbox.value.length > 0)
             {
                 if (isNaN(txtbox.value)) {
                     txtbox.value = "";
                     alert("Please enter number with one decimal places");
                     txtbox.focus();
                     return;
                 }
                 else if (parseFloat(txtbox.value) > 0)
                 {
                     txtbox.value = "";
                     alert("Please enter number with one decimal places. eg. 8.1");
                     txtbox.focus();
                     return;
                 }

                 var oRegExp = /^\s*\d+\.\d{1}\s*$/;
                   if (oRegExp.test(txtbox.value))
                     { }
                   else {

                         txtbox.value = "";
                         alert("Please enter number with one decimal places");
                         txtbox.focus();
                     }
               }
         }

Upvotes: 1

Views: 431

Answers (2)

Toto
Toto

Reputation: 91518

I'd do:

/^\d+(?:\.\d)?$/

explanation:

The regular expression:

(?-imsx:^\d+(?:\.\d)?$)

matches as follows:

NODE                     EXPLANATION
----------------------------------------------------------------------
(?-imsx:                 group, but do not capture (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n) (matching whitespace and #
                         normally):
----------------------------------------------------------------------
  ^                        the beginning of the string
----------------------------------------------------------------------
  \d+                      digits (0-9) (1 or more times (matching
                           the most amount possible))
----------------------------------------------------------------------
  (?:                      group, but do not capture (optional
                           (matching the most amount possible)):
----------------------------------------------------------------------
    \.                       '.'
----------------------------------------------------------------------
    \d                       digits (0-9)
----------------------------------------------------------------------
  )?                       end of grouping
----------------------------------------------------------------------
  $                        before an optional \n, and the end of the
                           string
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------

Upvotes: 0

elclanrs
elclanrs

Reputation: 94131

This regex should do:

/^\d*\.?\d$/

Demo: http://jsbin.com/ovaVAfU/1/edit

Upvotes: 2

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