The typeof operator is used to determine the data type of its argument (it returns a string). A literal or a data structure, such as a variable, a function, or an object, can be used as the operand. The operation returns the data type.
typeof operand
or
typeof (operand)
typeof can return six different values: object, boolean, function, number, string, and undefined. The typeof operator can yield a variety of values, as shown in the table below.
The typeof operator returns a string that specifies the type of the undeclared operand.
The typeof operator has the following syntax: typeof operand
The operand is either a variable name or a value in this case.
You're probably wondering why we need it.
A dynamically typed language is Javascript. So, what does this imply?
This implies that when a developer creates a variable, he or she does not give a type to it. A variable's type can vary over the course of a programme since it is not limited in this way.
var x = 123; x = ‘string'; x = ‘string'; x = ‘string'; x = ‘string'; x = ‘string'; x
While you can see, a variable in JavaScript can change types as the programme executes. As a programmer, this might be difficult to keep track of, which is where the typeof operator comes in handy.
Another application of the typeof operator is to ensure that a variable is declared before accessing it in your code. This can assist prevent software problems caused by trying to access a variable that isn't declared.
function(x) {
