What does NaN return in JavaScript?

The isNaN() function determines whether a value is an illegal number (Not-a-Number). This function returns true if the value equates to NaN. Otherwise it returns false.

Is NaN type number?

By definition, NaN is the return value from operations which have an undefined numerical result. NaN. It is still a numeric data type , but it is undefined as a real number .

Is NaN a number in JS?

Tip: In JavaScript, the value NaN is considered a type of number.

What does Typeof NaN return?

NaN just means the specific value cannot be represented within the limitations of the numeric type (although that could be said for all numbers that have to be rounded to fit, but NaN is a special case).

What is NaN type in JavaScript?

NaN is a property of the global object. In other words, it is a variable in global scope. The initial value of NaN is Not-A-Number — the same as the value of Number. NaN . In modern browsers, NaN is a non-configurable, non-writable property.

Is NaN a data type?

In computing, NaN (/næn/), standing for Not a Number, is a member of a numeric data type that can be interpreted as a value that is undefined or unrepresentable, especially in floating-point arithmetic. Quiet NaNs are used to propagate errors resulting from invalid operations or values.

How is NaN used in JavaScript?

In JavaScript, NaN stands for Not a Number. It represents a value which is not a valid number. It can be used to check whether a number entered is a valid number or not a number.

What is typeof null and typeof function?

In the first implementation of JavaScript, JavaScript values were represented as a type tag and a value. The type tag for objects was 0. null was represented as the NULL pointer (0x00 in most platforms). Consequently, null had 0 as type tag, hence the “object” typeof return value. ( reference)

What is Typeof in JavaScript?

typeof is a JavaScript keyword that will return the type of a variable when you call it. You can use this to validate function parameters or check if variables are defined. There are other uses as well. The typeof operator is useful because it is an easy way to check the type of a variable in your code.