1 Null Vs Undefined
A null means absence of a value. It means we can define a variable but have not assigned any value, so the value will be absent.
Double equals use for value equality. This means that before checking the values, it converts the types of the variables to match each other.
Triple equals do not perform type coercion. It will verify whether the variables compared have both the same value and the same type.
3 global variable, global scope
A variable declared outside a function, its called global scope. All other scripts and functions can access these global scope variables.
4 call(), apply() and bind() method
5 let and const
Const is similar to var or let declarations. The const makes a variable a constant where its value cannot be changed. Const variables have the same scoping rules as let variables.
6 Arrow Function
DOM means Document Object Model. DOM is use for programming interface for HTML and XML documents. The DOM represents a document as a tree of nodes. The DOM is cross-platform and language-independent ways of manipulating DOM tree.
API means Application Programming Interface. An API is a set of functions that allows applications to access data and interact with external software components, operating systems, or microservices.
9 callback function
10 This keyword