Micha
Micha
Programming language:Javascript
2021-05-15 18:00:48
0
Q:

js is number

Cromo
Cromo
Code: Javascript
2021-02-02 12:39:05 
// The first 2 Variations return a Boolean
// They just work the opposite way around

// IsInteger
if (Number.isInteger(val)) {
	// It is indeed a number
}

// isNaN (is not a number)
if (isNaN(val)) {
	// It is not a number
}

// Another option is typeof which return a string
if (typeof(val) === 'number') {
	// Guess what, it's a bloody number!
}
14
Elaine
Elaine
Code: Javascript
2021-01-25 14:52:30 
Number.isInteger(value)

//returns a Boolean
7
Don
Don
Code: Javascript
2021-05-19 16:15:38 
function isNumber(n) { return /^-?[\d.]+(?:e-?\d+)?$/.test(n); } 

------------------------

isNumber('123'); // true  
isNumber('123abc'); // false  
isNumber(5); // true  
isNumber('q345'); // false
isNumber(null); // false
isNumber(undefined); // false
isNumber(false); // false
isNumber('   '); // false
5
user307254
user307254
Code: Javascript
2021-01-30 09:39:00 
// The Number.isInteger() checks to see if the passed value is an integer
// Returns true or false

Number.isInteger(2); //True
Number.isInteger(90); //True
Number.isInteger("37"); //False
Number.isInteger(false); //false
2
ErikE
ErikE
Code: Javascript
2021-05-16 21:52:00 
Number.isInteger(123) //true
Number.isInteger(-123) //true
Number.isInteger(5-2) //true
Number.isInteger(0) //true
Number.isInteger(0.5) //false
Number.isInteger('123') //false
Number.isInteger(false) //false
Number.isInteger(Infinity) //false
Number.isInteger(-Infinity) //false
Number.isInteger(0 / 0) //false
2
sea shell
sea shell
Code: Javascript
2021-01-15 20:03:19 
if (!isNaN(number)){
	// is number
}
0
Zulkanien
Zulkanien
Code: Javascript
2021-01-15 20:05:52 
Number.isInteger(value)
0
VSr
VSr
Code: Javascript
2021-08-02 10:52:16 

<html>
<head></head>
<body>
<h1>isNaN() example</h1>

<script type="text/javascript">
 var num1 = 100;
 if(isNaN(num1)){
    document.write(num1 + " is not a number <br/>");
 }else{
    document.write(num1 + " is a number <br/>");
 }
 
 var str1 = "mkyong"
 if(isNaN(str1)){
    document.write(str1 + " is not a number <br/>");
 }else{
    document.write(str1 + " is a number <br/>");
 }
</script>

</body>
</html>
0
zudora
zudora
Code: Javascript
2021-01-25 07:42:22 
The Number. isInteger() method determines whether a 
value an integer. 
This method returns true if the value is of the type 
Number, and an integer (a number without decimals). 
Otherwise it returns false.
-1

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