# .css-4zleql{display:block;}MrCatDev's Blog  # When should I use prefix increment operator (++i)?

Hossein Shourabi
·Feb 1, 2022·

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# When should I use prefix increment operator (++i)?

Sometimes I need to increment the original value first, then return it value. So this operator is exactly what I need.

## How it (++i) works?

Let's look at this example:

``````let i = 2;
let counter = ++i * 2;
``````

The perfix increment operator (++i) equivalent to:

``````i = i + 1;
/*
* i=> 3
*/
let counter = i * 2;
/*
*  counter => 3 * 2 = 6
*/
``````

As you can see the `i` incremented, then multiplication by 2

## More Example

In the following code, before starting the while loop, the `i` operand is incremented one step, then checked in the `while` condition.

``````let i = 0;
while (++i < 3) console.log(i);
``````

above example equivalent to:

``````let i = 0;
i = i + 1;
while ( i < 3) {
i = i + 1;
console.log(i)
};
``````

You can find a practical example in this article that I wrote it with JavaScript.

1- Mozila