Interfaces in typescript are a way to define the data types (string, number, boolean, etc.) It help us while writing complex application, you should alway use interface in your applications. It is a compile time construct hence it will not have generated code as type checking in Typescript is only done at compile time rather than runtime. There are some interesting real-life cases where you need to create more complex … Step 4 – Complex. Syntax: Single Interface Inheritance Child_interface_name extends super_interface_name Iterating over the keys and values in an object is a common operation that's surprisingly hard to write without type assertions in TypeScript. Mongoose provides a layer of abstraction over MongoDB that makes validation, casting & business logic boilerplate more enjoyable. This means that any object of type IEmployee must define the two properties and two methods. To clarify the term ‘nesting’, I simply mean that interface A contains a property, which is described by interface B. If you need some logic attached to an instance you should make a … so i want to make some kind of base interface/type that can have the properties extended based on the generic object it has. Tagged with javascript, typescript, webdev. So basically interface will tell you the details of a particular object that what are the properties does an object can have and what is the type of those properties. Typescript allows an interface to inherit from multiple interfaces. Suppose we created an interface 'I' with properties x and y. @M98 An interface can be used to describe a structure. Use the extends keyword to implement inheritance among interfaces. somekind like this: interface BaseObject