Javascript Approved Number in RegExp
This question already has an answer here:
change your function to
function myFunction()
{
var str = document.getElementById("number_field").value;
var res = str.replace(/[^0-9.}]/g,"");
if (res.indexOf('.') !== res.lastIndexOf('.')) {
document.getElementById("approved_number").innerHTML="";
} else {
document.getElementById("approved_number").innerHTML=res;
}
}
Example here:
http://jsbin.com/UNOHoYek/1
See http://jsbin.com/OKoJuloQ/3/ for a possible answer.
Changing user input without providing feedback is probably not a good idea.
Better to just handle what can be taken as a number and report the rest.
window.alert is just one way to report it.
The important bits are the conversion to Number and testing against NaN .
CODE (also available via link above)
<!DOCTYPE html>
<html>
<body>
<input type="text" value="" id="number_field">
<button onclick="myFunction()">Submit</button>
<p id="approved_number"></p>
<script>
function myFunction() {
try {
var str = document.getElementById("number_field").value;
// var res = str.replace(/[^0-9.}]/g,"");
var res = str;
if (Number.isNaN(Number(res))) {
window.alert(res + " is not a number (NaN)nOnly digits, decimal point,nand exponent (e.g. 3.2e4) are allowed");
} else {
document.getElementById("approved_number").innerHTML=Number(res).toString(10);
}
} catch (exception) {
window.alert(exception);
}
}
</script>
</body>
</html>
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