Javascript uses the isNaN () function to determine whether the variable is a number.

In javascript, The isNaN () function in javascript is introduced here.

Function:

The isNaN () function is used to check whether the parameter is a non-numeric value.

Syntax:

IsNaN (x) x is required. The value to be detected.

Return Value:

If x is a special non-numeric value NaN (or can be converted to such a value), the returned value is true. If x is another value, false is returned.

Note:

The isNaN () function can be used to determine whether the parameter is NaN. This value indicates an invalid number (for example, the result obtained after being divided by 0 ).
If the result of comparing NaN with any value (including its own) is false, you cannot use the = OR = Operator to determine whether a value is NaN. Because of this, the isNaN () function is required.