Consider the **do-while** loop. This loop is similar to the **while** loop but has a difference.

# Syntax
The **do-while** loop starts with the `do` keyword, includes the code block (`{}`), and ends with the `while` keyword followed by the condition (`()`) without the code block:

```javascript
do {
  // code block
} while (condition);
```

let a = 0;

do {
  console.log(a);
  a++;
} while (a <= 3 && a >= 1);

At the start, the variable `a` was equal to `0`, but the condition `a >= 1` was checked after the `a = a + 1` operation.



The **do** code block is always executed at least once:

// while loop
while (false) {
  console.log("while");  // not executed
}

// do-while loop
do {
  console.log("do-while");  // executed 1 time
} while (false);

> Note
>
> The **end of the command** (`;`) after the `do` code block will result in a `SyntaxError`.

First, let's get acquainted with JavaScript and look at its syntax. In this section, you will get a basic familiarity with the JavaScript syntax to make it easier to learn in detail later on.

Now it's time to learn about the data types that JavaScript works with. We'll start by looking at the difference between literals and variables, and then delve into the various data types.

We have become familiar with the various data types. Now, let's learn how to work with them by learning the operations we can perform with each data type.

Next, we will learn how to control the flow of execution. It's a straightforward process: we can tell the interpreter exactly what to do under certain conditions.

Next, we will explore how to shorten code using repetitive looped actions. We will examine the types of loops available in JavaScript and learn how to work with them.

Finally, to be able to write simple programs, we need to learn about functions that can make our lives much easier. We will learn how to create and use our functions.

while	do-while
Executes code block after the conditional checking.	Executes code block before the conditional checking.