JavaScript For Loop

A for loop is a control flow statement in programming that allows you to repeatedly execute a block of code as long as a specified condition is true. The syntax of a for loop consists of three parts: initialization, condition, and iteration. Here's the basic structure:

for (initialization; condition; iteration) {
  // Code to be executed in each iteration
}

1. Initialization: Typically, this part is used to initialize a counter variable. It runs once at the beginning of the loop.
2. Condition: The loop continues as long as this condition is true. If the condition evaluates to false, the loop exits.
3. Iteration: This part is executed after each iteration of the loop. It is commonly used to update the counter variable.

Example:

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

In this example:

• let i = 1 initializes a counter variable i to 1.
• i <= 5 is the condition that specifies when the loop should continue.
• i++ increments the counter variable by 1 after each iteration.

The loop will execute five times, printing the numbers 1 to 5.

Examples:

Iterating Over an Array:

const fruits = ["apple", "banana", "orange"];

for (let i = 0; i < fruits.length; i++) {
  console.log(fruits[i]);
}

Nested Loops:

for (let i = 1; i <= 3; i++) {
  for (let j = 1; i <= 3; j++) {
    console.log(`i: ${i}, j: ${j}`);
  }
}

Skipping Iteration (using continue):

for (let i = 1; i <= 5; i++) {
  if (i === 3) {
    continue; // Skip iteration when i is 3
  }
  console.log(i);
}

Breaking Out of a Loop (using break):

for (let i = 1; i <= 5; i++) {
  if (i === 4) {
    break; // Exit the loop when i is 4
  }
  console.log(i);
}

for loops are powerful constructs for iterating over sequences, such as arrays, and performing repetitive tasks. They are widely used in programming to automate processes that involve repetitive actions.