How to check for `Nan` in JavaScript?
What is NaN?
- In JavaScript, NaN is kind of a value (an invalid number).
- NaN stands for “Not a Number”.
- You get NaN when you try to do some mathematical operations on values that are not Numbers.
How to detect Nan in JavaScript?
How to Detect NaN. In JavaScript, NaN is a special value. The value NaN represents the result of an arithmetic expression that can't actually be represented. For example, let result = 0/0; console.log(result); // returns, NaN Also, if we perform any arithmetic operations with NaN, it will always result in a NaN. console.log(NaN + 3); // returns ...
How do you test for Nan in JavaScript?
isNaN ()
- Syntax. The value to be tested.
- Description. Unlike all other possible values in JavaScript, it is not possible to use the equality operators (== and ===) to compare a value against NaN to determine whether the ...
- Examples. ...
- Specifications
- See also
What is the right way to handle Nan in Java?
- The numerical comparison operators <, <=, >, and >= always return false if either or both operands are NaN. ( §15.20.1)
- The equality operator == returns false if either operand is NaN.
- The inequality operator != returns true if either operand is NaN . ( §15.21.1)
How does nan work in Javascript?
Generally, NaN means Not a Number; it’s most probably used to indicate whether the method contains either error or any exceptions that occurred in the condition loop for the functions.
Conclusion
JavaScript uses a different set of built-in methods; among that isNaN () is one of the frequent methods and values for comparing the numeric and non-numeric values in the applications. If the requirement happens, it should be validated in the client browser with the help of predefined conditions.
Recommended Articles
This is a guide to JavaScript nan. Here we discuss How does nan work in Javascript and Examples along with the codes and outputs. You may also have a look at the following articles to learn more –
isNan () Method
As you can see numbers will return false as they are not NaN even if, the number is in the form of string. Any string (word or sentence) will return true as it is NaN
Here comes, something that contradicts
As discussed earlier, isNan () will return true if a value is Not-a-Number (NaN) Number.isNaN () method while is completely opposite of isNaN method, here Number.isNaN () will return true if number is NaN
Introduction to JavaScript NaN
JavaScript has the number type that allows you to represent numbers including integer and floating-point numbers. And JavaScript number has a special value called NaN, which stands for N ot- a – N umber.
Checking if a value is NaN
JavaScript provides you with the global function isNaN () that returns true if its argument is NaN:
Why use NaN
JavaScript uses NaN as the result of a failed operation on numbers including:
Operations return NaN
In JavaScript, you can convert a numeric string to a number. For example:
Summary
NaN stands for Not-a-Number. It is a special value of the NaN property of the global object.
What is a NaN?
NaN is a global property that represents the value of Not-A-Number, hence the name. It is possible to get the value NaN returned when doing an arithmetic operation or coercing some value to a number. Here are some operations that result in NaN
What to do when working with isNaN?
When working with isNaN you need to beware of the coercion of the value to a numeric-value. Remember some values cannot be coerced to a numeric-value and will result in NaN so even though your argument to isNaN might not have been NaN it could become one.
Is NaN a bad JavaScript?
NaN has a bad reputation for being tricky, however, if you familiarize yourself with the following few facts you will be able to work with NaN with no issue. NaN unlike it's name is actually from the type Number. NaN is the only value in JavaScript that does not equal itself.
Is isnan a JavaScript function?
For the reasons that should be clear from above using isNaN is not ideal. This is why Number.isNaN has been added to JavaScript starting from ES6. The main difference between the two functions is that Number.isNaN does not convert its argument to a numeric-value before determining whether it is NaN.