Typescript Functions
Duration : 00:01:45
Named Function:
Named functions are defined with a specific name and can be called using that name. They are typically used for reusable blocks of code.Example:
function greet(name: string): string {
return `Hello, ${name}!`;
}
const message = greet("Alice");
console.log(message); // Output: Hello, Alice!
Function Expression:
Function expressions involve defining a function within an expression. They can be assigned to variables and passed around as values.Example:
const add = function (a: number, b: number): number {
return a + b;
};
const result = add(3, 5);
console.log(result); // Output: 8
Arrow Function:
Arrow functions are a concise way to write functions in TypeScript, especially useful for anonymous functions and when you want to maintain the lexical context (this).Example:
const multiply = (a: number, b: number): number => a * b;
const product = multiply(4, 6);
console.log(product); // Output: 24
Function Parameters:
Function parameters are used to pass values into functions. They can have types and be optional or have default values.Example:
function greetWithMessage(name: string, message: string = "Hello"): string {
return `${message}, ${name}!`;
}
const welcome = greetWithMessage("Bob");
console.log(welcome); // Output: Hello, Bob!
Function Overloads:
Function overloads allow you to define multiple type signatures for a function, ensuring it can handle different argument types.Example:
function getLength(input: string): number;
function getLength(input: any[]): number;
function getLength(input: any): number {
if (typeof input === "string") {
return input.length;
} else if (Array.isArray(input)) {
return input.length;
} else {
return 0;
}
}
console.log(getLength("Hello")); // Output: 5
console.log(getLength([1, 2, 3])); // Output: 3
Still have some questions? Let's discuss.
CONTACT US