T040 Mastering Methods and Functions

In this assignment, you’ll delve into the world of TypeScript methods and functions. You’ll practice creating and invoking functions, working with lambda expressions, and exploring advanced function concepts.

Setup

1. Create a new TypeScript file

Basic Methods

1. Simple Function: Create a function named greet that takes a name parameter of type string and returns a greeting message. Invoke the function and print the result.
2. Function with Multiple Parameters: Create a function named add that takes two parameters of type number and returns their sum. Invoke the function with different arguments and print the results.

Lambda Expressions

1. Simple Lambda: Create a lambda function named square that takes a number and returns its square. Invoke the function and print the result.
2. Lambda with Multiple Statements: Create a lambda function named describe that takes a name and age parameter and returns a string describing the person. The function should have multiple statements. Invoke the function and print the result.

Advanced Function Concepts

1. Function as a Parameter: Create a function named operate that takes two numbers and a function as parameters. This function should apply the provided function to the two numbers and return the result. Test this with simple functions like addition and multiplication.
2. Function Returning a Function: Create a function named getFunction that generates a random number (1 or 2). If the number is 1, it should return a function that calculates the square of a number. If the number is 2, it should return a function that calculates the cube of a number. Invoke getFunction and then invoke the returned function, printing the result.

Challenge: Dynamic Function Invocation

1. Dynamic Function Selector: Based on the previous task, after getting the function from getFunction, invoke it with a range of numbers from 1 to 5 using a loop, printing the results.

Solution

Solution

Basic Methods

function greet(name: string): string {
    return `Hello, ${name}!`;
}
console.log(greet("Alice"));

function add(a: number, b: number): number {
    return a + b;
}
console.log(add(5, 3));

Lambda Expressions

let square = (x: number) => x * x;
console.log(square(4));

let describe = (name: string, age: number) => {
    return `${name} is ${age} years old.`;
}
console.log(describe("Bob", 25));

Advanced Function Concepts

function operate(x: number, y: number, operation: (a: number, b: number) => number): number {
    return operation(x, y);
}
console.log(operate(4, 5, (a, b) => a + b));
console.log(operate(4, 5, (a, b) => a * b));

function getFunction(): (x: number) => number {
    let randomNumber = Math.floor(Math.random() * 2) + 1;
    if (randomNumber === 1) {
        return x => x * x; // square
    } else {
        return x => x * x * x; // cube
    }
}
let randomFunction = getFunction();
console.log(randomFunction(3));

Challenge: Dynamic Function Invocation

for (let i = 1; i <= 5; i++) {
    console.log(randomFunction(i));
}