TypeScript Object Interfaces vs. Intersections Last Updated : 28 Apr, 2025 Summarize Comments Improve Suggest changes Share Like Article Like Report TypeScript offers several features when it comes to defining complex data structures. In TypeScript, Object Interface and Intersections are two different features that serve different purposes when it comes to defining complex data structures. Object InterfacesObject Interfaces are used to define the shape or structure of an object.They define the properties with the types that an object should contain.We use the 'interface' keyword to declare an object interface followed by the interface name and its properties.They can be implemented by other interfaces and classes, promoting code reusability and maintainability.Example: This example shows the use of the TypeScript Interfaces. JavaScript interface Employee { eid: string, name: string } const emp: Employee = { eid: "E54321", name: "Ravi" }; console.log(emp); Output: { eid: 'E54321', name: 'Ravi' }IntersectionsIntersections allow us to combine multiple types into a single type.We use the '&' operator to merge all properties and methods of each type involved.Intersections are used to compose multiple types by merging existing types or interfaces. Example: This example shows the use of TypeScript intersections JavaScript interface Employee { eid: string, name: string } interface Address { street: string; city: string; } type EmployeeWithAddress = Employee & Address; const employeeWithAddress: EmployeeWithAddress = { eid: "E54321", name: "Bob", street: "123 BHU Lanka", city: "Varanasi", }; console.log(employeeWithAddress); Output: { eid: 'E54321', name: 'Bob', street: '123 BHU Lanka', city: 'Varanasi'}Object Interfaces vs. Intersections:Feature Interface Intersection Purpose Define shape of an object. Combines multiple types into single type. Declaration Syntax Uses 'interface' keyword. Uses '&' Operator. Structure Defines properties with their types. Merges properties and methods from multiple types. Extensibility Can be extended and implemented by other interfaces or classes. Cannot be extended. Composition Support extending interface with help of inheritance. Combines multiple type or interfaces without inheritance. Object Instances Used to declare objects that conform to the interface. Not used directly to declare objects. Reusability Objects are reusable due to inheritance. Used to create advance composite types. Use Cases Defining individual object structures. Used when we want to create a new type that has characteristics of multiple types. Conclusion: TypeScript object interfaces are used to define the structure of individual objects, while intersections combine multiple types to create new composite types. In many cases, we might use both object interfaces and intersections depending on the specific requirements of our applications. Understanding when and how to use these powerful features is essential for building robust applications using TypeScript. Comment More infoAdvertise with us Next Article TypeScript Interface vs Type Statements P pranjalisingh1201 Follow Improve Article Tags : TypeScript Geeks Premier League 2023 Similar Reads TypeScript Interface vs Type Statements In TypeScript, interface and type are used to define the structure of objects and custom types. While interfaces enforce contracts for classes and support multiple inheritance, types offer flexibility for defining complex and reusable type aliases. Each serves distinct use cases.Table of ContentInte 3 min read TypeScript Object Intersection Types In TypeScript, Object Intersection Types are a way to create new types by combining multiple types into a single type. This is done using the & (ampersand) operator. Intersection types allow you to express that an object must have all the properties and methods of each type in the intersection. 3 min read Union Type to Intersection Type in TypeScript To Transform union type to intersection type we have different approaches. In this article, we are going to learn how to Transform union type to intersection type. Below are the approaches used to Transform union type to intersection type: Table of Content Using Distributive Conditional TypesUsing C 3 min read TypeScript Interfaces Type TypeScript Interfaces Type offers an alternative method for defining an object's type, allowing for a distinct naming approach. Syntax:interface InterfaceName { property1: type1; property2?: type2; readonly property3: type3; // ... method1(): returnType1; method2(): returnType2; // ...}Parameters:in 2 min read What are intersection types in Typescript ? In Typescript, Although intersection and union types are similar, they are employed in completely different ways. An intersection type is a type that merges several kinds into one. This allows you to combine many types to create a single type with all of the properties that you require. An object of 3 min read How to Define Interfaces for Nested Objects in TypeScript ? In TypeScript, defining interfaces for nested objects involves specifying the structure of each level within the object hierarchy. This helps ensure that the nested objects adhere to a specific shape or pattern. Here are step-by-step instructions on how to define interfaces for nested objects in Typ 2 min read Like