Question

140

Regular Expression in JavaScript to allow only numbers with optional 2 decimals

rated 0 times [ 143] [ 3] / answers: 1 / hits: 56886 / 11 Years ago, sat, january 18, 2014, 12:00:00

I want to write a regular expression in which allows

backspace

0-9 digits

optional fractional part with two decimals (no limit on integral part how many digits there can be)

For example:

Allowed lists is [12 , 232.0 , 23.(with only dot) , 345.09 , 78.23 , 134.00 , 0.21 , .21 , .02 , .01 .12 ]

Not allowed are [12.878 , 34.343.334 , .0003 ]

The use of this regular expression would be like on javascript event

<input type=text  onKeyPress=validatenumber(event);   /><br>

My code is

function validatenumber(evt) {

  var theEvent = evt || window.event;

  var key = theEvent.keyCode || theEvent.which;

  key = String.fromCharCode( key );

  var regex = /^[0-9b]+$/;    // allow only numbers [0-9] 

  if( !regex.test(key) ) {

    theEvent.returnValue = false;

    if(theEvent.preventDefault) theEvent.preventDefault();

  }

}

I want to change only this line with the new regex:

var regex = /^[0-9b]+$/;    // allow only numbers [0-9]

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shantelc

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4 Years ago

answered 11 Years ago rocioblancac · Accepted Answer

find the final solution at least

<input id=txtId type=text onkeyup=NumAndTwoDecimals(event , this);></input>

and the

 function NumAndTwoDecimals(e , field) {

    var val = field.value;

    var re = /^([0-9]+[.]?[0-9]?[0-9]?|[0-9]+)$/g;

    var re1 = /^([0-9]+[.]?[0-9]?[0-9]?|[0-9]+)/g;

    if (re.test(val)) {

        //do something here



    } else {

        val = re1.exec(val);

        if (val) {

            field.value = val[0];

        } else {

            field.value = ;

        }

    }

}