Practical Example of Using Loops

Let's put loops into practice with several real-world examples that combine everything we've learned.

Example 1: Sum of Numbers

// Calculate the sum of numbers 1 to 100
let total = 0;

for (let i = 1; i <= 100; i++) {
    total += i;
}

console.log("Sum of 1-100:", total);  // 5050

Example 2: Multiplication Table

let number = 7;

console.log(`Multiplication table for ${number}:`);
for (let i = 1; i <= 10; i++) {
    console.log(`${number} x ${i} = ${number * i}`);
}

Example 3: FizzBuzz

for (let i = 1; i <= 30; i++) {
    if (i % 3 === 0 && i % 5 === 0) {
        console.log("FizzBuzz");
    } else if (i % 3 === 0) {
        console.log("Fizz");
    } else if (i % 5 === 0) {
        console.log("Buzz");
    } else {
        console.log(i);
    }
}

Example 4: Find Max in Array

let numbers = [23, 45, 12, 67, 34, 89, 5, 56];
let max = numbers[0];

for (let i = 1; i < numbers.length; i++) {
    if (numbers[i] > max) {
        max = numbers[i];
    }
}
console.log("Maximum:", max);  // 89

Example 5: Reverse a String

let original = "JavaScript";
let reversed = "";

for (let i = original.length - 1; i >= 0; i--) {
    reversed += original[i];
}
console.log(reversed);  // "tpircSavaJ"

Example 6: Count Vowels

let text = "Hello World JavaScript";
let vowels = "aeiouAEIOU";
let count = 0;

for (let char of text) {
    if (vowels.includes(char)) {
        count++;
    }
}
console.log("Vowel count:", count);  // 7