⟩ How can I know that a variable is a number or not using a JavaScript?
Answer 1:
bool is_numeric( mixed var)
Returns TRUE if var is a number or a numeric string, FALSE otherwise.
Answer 2:
Definition and Usage
The isNaN() function is used to check if a value is not a number.
Syntax
isNaN(number)
Parameter Description
number Required. The value to be tested