So in javascript, there is an operator to check the instance of a class and check the type of a value within a variable.
1. Typeof
So it is basically an operator to check the datatype of a value present inside a variable and respond to what type is present inside the variable.
Example - string:
var name = 'neo'
console.log(typeof name)Output: string
Example - number:
var num = 21
console.log(typeof num)Output: number
Example - boolean:
var name = true
console.log(typeof name)Output: boolean
Example - object:
var ra = [12,2,2,1]
console.log(typeof ra)Output: object
So you might get the idea right. It basically gets the data type of the value that the variable is holding.
2. Instanceof
It generally finds or verifies out whether the object created from a class is actually an instance of the respective class or not.
Example: When object is instance of class
class matrix {
}
ma = new matrix();
console.log(ma instanceof matrix)Output: true
Here 'ma' is an instance of the class matrix because it was used to create an object from the matrix class.
Example: When object is not the instance of class
class matrix {
}
class zion {
}
ma = new matrix();
console.log(ma instanceof zion)Output: false
Here it represents the pessimistic scenario where we have given zion class name for ma object of class matrix and check whether ma is instance of zion or not, which will eventually return false.