JavaScript While Loop

A while loop is another type of control flow statement in programming that repeatedly executes a block of code as long as a specified condition is true. The loop continues to execute until the condition becomes false. The basic syntax of a while loop is as follows:

while (condition) {
  // Code to be executed as long as the condition is true
}

Here's a simple example of a while loop that prints the numbers 1 to 5:

let i = 1;

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

In this example:

• i is initialized to 1 before the while loop.
• The condition i <= 5 is checked before each iteration. If it evaluates to true, the code inside the loop is executed.
• i++ increments the value of i after each iteration.

The loop will print the numbers 1 to 5, similar to the for loop example.

Examples:

Iterating Over an Array:

const colors = ["red", "green", "blue"];
let index = 0;

while (index < colors.length) {
  console.log(colors[index]);
  index++;
}

Infinite Loop (Be Careful!):

let counter = 0;

while (true) {
  console.log(counter);
  counter++;

  if (counter === 5) {
    break; // Ensure the loop doesn't run indefinitely
  }
}

Using continue and break:

let num = 1;

while (num <= 10) {
  if (num % 2 === 0) {
    num++;
    continue; // Skip even numbers
  }

  console.log(num);

  if (num === 7) {
    break; // Exit the loop when num is 7
  }

  num++;
}

while loops are useful when the number of iterations is not known in advance or when the loop should continue until a specific condition is met. It's important to ensure that the condition eventually becomes false to avoid infinite loops.