Loops

Looping is a foundational concept in programming, allowing for repeated execution of a block of code. TypeScript, building upon JavaScript, offers a variety of loop constructs to handle different scenarios. This tutorial will delve into the primary loop mechanisms in TypeScript, discussing their syntax and use cases.

for Loop:

The traditional for loop is composed of an initializer, a condition, and an increment expression. It's perfect for cases where you know in advance how many iterations you need.

for (let i = 0; i < 5; i++) {
    console.log(i);
}

This prints numbers 0 through 4.

for...of Loop

Ideal for iterating over elements in arrays or other iterable objects, the for...of loop offers simplicity.

const fruits = ['apple', 'banana', 'cherry'];
for (let fruit of fruits) {
    console.log(fruit);
}

This prints 'apple', 'banana', and 'cherry'.

for...in Loop

This loop iterates over the properties (keys) of an object, making it suitable for object property traversal.

const person = {
    name: "John", 
    age: 30, 
    city: "New York"
};

for (let key in person) {
    console.log(key, person[key]);
}

This prints 'name John', 'age 30', and 'city New York'.

while and do...while Loops

The while loop continues executing its block as long as its condition remains true. On the other hand, the do...while loop ensures the block gets executed at least once before checking the condition.

let count = 0;
while (count < 3) {
    console.log(count);
    count++;
}

This prints numbers 0, 1, and 2.

Familiarizing yourself with these loop constructs is crucial for robust TypeScript programming. They offer the versatility and power to address a broad range of iteration-based tasks and scenarios.

Exercise

Given an object representing a collection of books, use the for...in loop to print out each book's title and author.