![TypeScript Tutorial](/typescript/images/typescript-mini-logo.jpg)
- TypeScript Basics
- TypeScript - Home
- TypeScript - Overview
- TypeScript - Environment Setup
- TypeScript - Basic Syntax
- TypeScript vs. JavaScript
- TypeScript - Features
- TypeScript - Variables
- TypeScript - let & const
- TypeScript - Operators
- TypeScript Basic Types
- TypeScript - Types
- TypeScript - Type Annotations
- TypeScript - Type Inference
- TypeScript - Numbers
- TypeScript - Strings
- TypeScript - Boolean
- TypeScript - Arrays
- TypeScript - Tuples
- TypeScript - Enums
- TypeScript - Any
- TypeScript - Never
- TypeScript - Union
- TypeScript - Literal Types
- TypeScript - Symbols
- TypeScript - null vs. undefined
- TypeScript - Type Aliases
- TypeScript Control Flow
- TypeScript - Decision Making
- TypeScript - If Statement
- TypeScript - If Else Statement
- TypeScript - Nested If Statements
- TypeScript - Switch Statement
- TypeScript - Loops
- TypeScript - For Loop
- TypeScript - While Loop
- TypeScript - Do While Loop
- TypeScript Functions
- TypeScript - Functions
- TypeScript - Function Types
- TypeScript - Optional Parameters
- TypeScript - Default Parameters
- TypeScript - Anonymous Functions
- TypeScript - Function Constructor
- TypeScript - Rest Parameter
- TypeScript - Parameter Destructuring
- TypeScript - Arrow Functions
- TypeScript Interfaces
- TypeScript - Interfaces
- TypeScript - Extending Interfaces
- TypeScript Classes and Objects
- TypeScript - Classes
- TypeScript - Objects
- TypeScript - Access Modifiers
- TypeScript - Readonly Properties
- TypeScript - Inheritance
- TypeScript - Static Methods and Properties
- TypeScript - Abstract Classes
- TypeScript - Accessors
- TypeScript - Duck-Typing
- TypeScript Advanced Types
- TypeScript - Intersection Types
- TypeScript - Type Guards
- TypeScript - Type Assertions
- TypeScript Type Manipulation
- TypeScript - Creating Types from Types
- TypeScript - Keyof Type Operator
- TypeScript - Typeof Type Operator
- TypeScript - Indexed Access Types
- TypeScript - Conditional Types
- TypeScript - Mapped Types
- TypeScript - Template Literal Types
- TypeScript Generics
- TypeScript - Generics
- TypeScript - Generic Constraints
- TypeScript - Generic Interfaces
- TypeScript - Generic Classes
- TypeScript Miscellaneous
- TypeScript - Triple-Slash Directives
- TypeScript - Namespaces
- TypeScript - Modules
- TypeScript - Ambients
- TypeScript - Decorators
- TypeScript - Type Compatibility
- TypeScript - Date Object
- TypeScript - Iterators and Generators
- TypeScript - Mixins
- TypeScript - Utility Types
- TypeScript - Boxing and Unboxing
- TypeScript - tsconfig.json
- From JavaScript To TypeScript
- TypeScript Useful Resources
- TypeScript - Quick Guide
- TypeScript - Useful Resources
- TypeScript - Discussion
TypeScript - Returning a Function
Functions may also return value along with control, back to the caller. Such functions are called as returning functions.
Syntax
function function_name():return_type { //statements return value; }
The return_type can be any valid data type.
A returning function must end with a return statement.
A function can return at the most one value. In other words, there can be only one return statement per function.
The data type of the value returned must match the return type of the function.
Example
//function defined function greet():string { //the function returns a string return "Hello World" } function caller() { var msg = greet() //function greet() invoked console.log(msg) } //invoke function caller()
The example declares a function greet(). The function’s return type is string.
Line function returns a string value to the caller. This is achieved by the return statement.
The function greet() returns a string, which is stored in the variable msg. This is later displayed as output.
On compiling, it will generate following JavaScript code −
//Generated by typescript 1.8.10 //function defined function greet() { return "Hello World"; } function caller() { var msg = greet(); //function greet() invoked console.log(msg); } //invoke function caller();
The output of the above code is as follows −
Hello World