How to use the typeof operator In Javascript
The typeof operator can be used to perform the type check of the passed value and compare it with the number type to check whether it is a number or not.
Syntax:
typeof testingValue;
Example: The below code example uses the typeof operator to check for the type of the passed value.
function isNumber(value){
try{
if(!(typeof value === 'number')){
throw new Error("Passed value is not a number");
}
console.log("Passed value is a number");
}
catch(error){
console.log("An error occurred: ", error.message);
}
}
isNumber(123);
isNumber("123");
isNumber("GFG");
Output
Passed value is a number An error occurred: Passed value is not a number An error occurred: Passed value is not a number
How to Check if a Value is a Number in JavaScript ?
To check if a value is a number in JavaScript, use the typeof operator to ensure the value’s type is ‘number’. Additionally, functions like Number.isFinite() and !isNaN() can verify if a value is a valid, finite number.
We can use the below methods to check whether the value is a number or not:
Table of Content
- Using the isNaN() method
- Using the typeof operator
- Using the Number.isInteger() method
- Using the Number.isFinite() method