JS Function to check whether the string is numeric

Javascript function to check the string in the textbox is numeric

function name : isNumber
parameters : Input control object and flag to allow decimal points

Function doesn't allow non numeric characters in the control

the function can be called on onKeyUp event of the control.


if permitDecimal = 0 then decimal point '.' is not allowed in string, else dot is allowed.


function isNumber( obj ,permitDecimal ){

var val = document.getElementById(obj).value ;
var te=val.match(/\d+\.?\d*/);
document.getElementById(obj).value=te;
val=te;

if(val!=""){
if( isNaN(val) ){
endOFString=val.length-1;
val=val.substring(0,endOFString);
}
if(!permitDecimal){
if(val){
val=val.toString();
document.getElementById(obj).value=val.replace(/\./g,'');
}
}else{
document.getElementById(obj).value=val;
}

}
}




Sample usage

<input id="txtpersontel" type="text" name="persontel" maxlength="20" style="width:125px"
onkeyUP=" isNumber('txtpersontel',0);">


Tweet