Learn The `while` Loop | Discovering Loops

The while loop is another kind of loop supported by most programming languages including JavaScript.

The while loop is mainly used when we want to execute a block of code as long as a condition is true. Although it may behave similar to a for loop in certain circumstances, it is mainly used in cases where we don't know exactly how many times a block of code needs to be executed.

The general syntax of a while loop is:

while(boolean_expression) {
  // code to execute
}

Note

If the condition of a while loop is always true, it will execute forever. Such a loop is known as an infinite loop.

The process of a while loop can be better understood by looking at it's flowchart:

Following is an example program which utilizes a while loop to find the first number that is divisible by both 11 and 12:


              123456
            
let i = 13;
while(i % 11 != 0 && i % 12 != 0) {
  i += 1;
}

console.log("The first number divisible by both 11 and 12 is:", i);

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Section 6. Chapter 3

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The while loop is another kind of loop supported by most programming languages including JavaScript.

The general syntax of a while loop is:

while(boolean_expression) {
  // code to execute
}

Note

If the condition of a while loop is always true, it will execute forever. Such a loop is known as an infinite loop.

The process of a while loop can be better understood by looking at it's flowchart:

Following is an example program which utilizes a while loop to find the first number that is divisible by both 11 and 12:


              123456
            
let i = 13;
while(i % 11 != 0 && i % 12 != 0) {
  i += 1;
}

console.log("The first number divisible by both 11 and 12 is:", i);

Everything was clear?

Thanks for your feedback!

Section 6. Chapter 3

The `while` Loop

1. What is the main difference between a `for` loop and a `while` loop?

2. How many times will the following loop execute?

3. What will happen if the condition in a `while` loop is always true?

Awesome!

The `while` Loop

1. What is the main difference between a `for` loop and a `while` loop?

2. How many times will the following loop execute?

3. What will happen if the condition in a `while` loop is always true?

The `while` Loop

1. What is the main difference between a for loop and a while loop?

2. How many times will the following loop execute?

3. What will happen if the condition in a while loop is always true?

Awesome!

The `while` Loop

1. What is the main difference between a for loop and a while loop?

2. How many times will the following loop execute?

3. What will happen if the condition in a while loop is always true?

1. What is the main difference between a `for` loop and a `while` loop?

3. What will happen if the condition in a `while` loop is always true?

1. What is the main difference between a `for` loop and a `while` loop?

3. What will happen if the condition in a `while` loop is always true?