How to write isNumber() in JavaScript?
First, there is no function like isNumeric in pure JavaScript. But jQuery has this function to check the integers.
but you could add your own function like below example:
function isNumeric(n) {
return !isNaN(parseFloat(n)) && isFinite(n);
}Complete Example of JavaScript IsNumeric
HTML example code:-
<!DOCTYPE html>
<html>
<body>
<script type="text/javascript">
function isNumeric(n) {
return !isNaN(parseFloat(n)) && isFinite(n);
}
var num = 10;
var check = isNumeric(num)
alert(check)
</script>
</body>
</html> Output:
NOTE: Since parseInt() is not a proper way to check for numeric it should NOT be used.
Q: How to Check if variable is a number in JavaScript?
Answer: You can use isinteger JavaScript Method:
<!DOCTYPE html>
<html>
<head>
<script>
var a = Number.isInteger(-7);
var b = Number.isInteger(-1.96);
alert(a)
</script>
</head>
</html>Read more:
Do comment if you have any question and suggestions on this tutorial.
Note: The All JS Examples codes are tested on the Safari browser (Version 12.0.2) and Chrome.
OS: macOS 10.14 Mojave
Code: HTML 5 Version