Operators and Loops in JavaScript

let first = "Hello";
let last = "World";
console.log(first + " " + last); // Hello World

let age = 18;
let status = (age >= 18) ? "Adult" : "Minor";
console.log(status); // Adult

8️⃣ Bitwise Operators ⚡

Operate on binary numbers.

📚 Best Practices

• ✅ Use === instead of == to avoid type coercion issues
• ✅ Group logical conditions with parentheses for clarity
• ✅ Avoid unnecessary bitwise operators unless needed
• ✅ Remember string concatenation with + is different from numeric addition

📌 Summary: JavaScript operators

• 🧮 Perform calculations (Arithmetic)
• 🖋 Assign values (Assignment)
• ⚖ Compare values (Comparison)
• 🧠 Combine conditions (Logical)
• 📄 Manipulate strings (String Operators)
• ❓ Make decisions (Ternary)
• 🏷 Check types (Type Operators)
• ⚡ Work with binary values (Bitwise)

🔄 Loops in JavaScript

In JavaScript, loops are used to execute a block of code multiple times until a certain condition is met.

They help avoid writing repetitive code.

📜 Why Use Loops?

Instead of writing:

console.log(1);
console.log(2);
console.log(3);
We can write:
javascript
CopyEdit
for (let i = 1; i <= 3; i++) {
    console.log(i);
}

This saves time and makes code shorter & dynamic.

📂 Types of Loops in JavaScript

1️⃣ for Loop

Runs code a specific number of times.

📌 Syntax

for (initialization; condition; increment/decrement) {
    // code block
}

📌 Example

for (let i = 1; i <= 5; i++) {
    console.log(i);
}
// Output: 1 2 3 4 5

2️⃣ while Loop

Runs as long as the condition is true.

📌 Syntax

while (condition) {
    // code block
}

📌 Example

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

3️⃣ do...while Loop

Executes the code block at least once before checking the condition.

📌 Syntax

do {
    // code block
} while (condition);

📌 Example

let i = 1;

do {
    console.log(i);
    i++;
} while (i <= 5);

4️⃣ for...in Loop 🏷

Used to loop through object properties.

📌 Example

let person = {name: "John", age: 25, city: "Delhi"};
for (let key in person) {
    console.log(key, ":", person[key]);
}

📌 Output

name : John
age : 25
city : Delhi

5️⃣ for...of Loop 📦

Used to loop through iterable objects like arrays, strings, etc.

📌 Example

let fruits = ["Apple", "Banana", "Mango"];
for (let fruit of fruits) {
    console.log(fruit);
}

📌 Output

Apple
Banana
Mango

🔄 Loop Control Statements

JavaScript provides ways to control loops.

🔹 break

Stops the loop immediately.

for (let i = 1; i <= 10; i++) {
    if (i === 5) break;
    console.log(i);
}
// Output: 1 2 3 4

🔹 continue

Skips the current iteration and moves to the next.

for (let i = 1; i <= 5; i++) {
    if (i === 3) continue;
    console.log(i);
}
// Output: 1 2 4 5

📚 Best Practices

• ✅ Avoid infinite loops (make sure conditions will be false at some point).
• ✅ Use for...of for arrays, and for...in for objects.
• ✅ Prefer forEach() for cleaner array iteration when the index is not needed.

📌 Summary Table of Loops in JavaScript