Loops are used in JavaScript to repeat a block of code multiple times until a certain condition is met. They help reduce redundancy and make your code more efficient.
This blog explains the different types of loops with examples.
⭐ 1. Why Use Loops?
Without loops, you would have to write repetitive code:
console.log("Hello");
console.log("Hello");
console.log("Hello");
With loops, the same task can be done in fewer lines:
for(let i = 0; i < 3; i++){
console.log("Hello");
}
⭐ 2. The for Loop
The for loop is commonly used when you know how many times you want to repeat the code.
Syntax:
for(initialization; condition; increment/decrement){
// code to run
}
Example:
for(let i = 1; i <= 5; i++){
console.log("Number " + i);
}
⭐ 3. The while Loop
The while loop repeats as long as the condition is true. Use it when you don’t know how many iterations will be needed.
Syntax:
while(condition){
// code to run
}
Example:
let i = 1;
while(i <= 5){
console.log("Number " + i);
i++;
}
⭐ 4. The do-while Loop
The do-while loop runs at least once and then checks the condition.
Syntax:
do {
// code to run
} while(condition);
Example:
let i = 1;
do {
console.log("Number " + i);
i++;
} while(i <= 5);
⭐ 5. Loop Control Statements
break
Stops the loop immediately.
for(let i = 1; i <= 5; i++){
if(i === 3) break;
console.log(i);
}
// Output: 1, 2
continue
Skips the current iteration and continues with the next.
for(let i = 1; i <= 5; i++){
if(i === 3) continue;
console.log(i);
}
// Output: 1, 2, 4, 5
⭐ 6. Nested Loops
Loops can be placed inside other loops.
Example:
for(let i = 1; i <= 3; i++){
for(let j = 1; j <= 2; j++){
console.log(`i=${i}, j=${j}`);
}
}
⭐ 7. Looping Through Arrays
for loop
let fruits = ["Apple", "Banana", "Mango"];
for(let i = 0; i < fruits.length; i++){
console.log(fruits[i]);
}
for…of loop (ES6)
for(let fruit of fruits){
console.log(fruit);
}
forEach method
fruits.forEach(fruit => console.log(fruit));
⭐ Conclusion
Loops are essential in JavaScript for reducing repetitive code and handling tasks dynamically. Understanding different types of loops and their control statements helps in building efficient programs.
📌 Citations
🔗 View other articles about Javascript:
https://savanka.com/category/learn/js/
🔗 External Javascript Documentation:
https://www.w3schools.com/js/