Loops in JavaScript | Day 36 | For loop And While Loop | Web development course 2023

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Loops in JavaScript
Loops are control flow statements that allow you to execute a block of code repeatedly until a specific condition is met. They are essential for automating tasks and processing large amounts of data. There are three primary loop types in JavaScript:

1. For loop:

The for loop iterates a block of code a specified number of times. It uses the following syntax:

JavaScript
for (initial_expression; condition; update_expression) {
// code to be executed
}
Use code with caution. Learn more
initial_expression: Initializes a counter variable.
condition: Determines whether the loop continues.
update_expression: Updates the counter variable after each iteration.
2. While loop:

The while loop iterates a block of code as long as a condition is true. It uses the following syntax:

JavaScript
while (condition) {
// code to be executed
}
Use code with caution. Learn more
condition: Determines whether the loop continues.
3. Do...while loop:

The do...while loop is similar to the while loop, but it executes the code block at least once before checking the condition. It uses the following syntax:

JavaScript
do {
// code to be executed
} while (condition);
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condition: Determines whether the loop continues.
Here are some examples of each loop type:

1. For loop:

JavaScript
for (let i = 0; i < 5; i++) {
console.log(i); // Outputs: 0, 1, 2, 3, 4
}
Use code with caution. Learn more
2. While loop:

JavaScript
let count = 0;
while (count < 5) {
console.log(count); // Outputs: 0, 1, 2, 3, 4
count++;
}
Use code with caution. Learn more
3. Do...while loop:

JavaScript
let input;
do {
input = prompt("Enter a number:");
} while (isNaN(input)); // Ensures valid input

console.log("You entered:", input);
Use code with caution. Learn more
In addition to these basic loop types, JavaScript offers several other loop variations and control flow statements for more complex situations. These include:

for...in loop: Iterates over the properties of an object.
for...of loop: Iterates over the values of an iterable object.
break statement: Exits the current loop.
continue statement: Skips the current iteration of the loop and continues to the next.