# Number function

The `Number` function converts a passed value to a number. In the case of a string, whitespace characters are cut off at the edges, then, if the string can be converted to a number, then this number is returned, and if not, it returns `NaN`. A `true` value is converted to the number `1`, a `false` value - to the number `0`. Objects during numerical conversions turn into `NaN`.

## Syntax

`Number(what to convert);`

## Example

Let's convert the boolean `true` value to a number:

`Number(true);`

The code execution result:

`1`

## Example

Now let's convert the boolean `false` value:

`Number(false);`

The code execution result:

`0`

## Example

Let's enter the string containing a number into a function parameter:

`Number('53');`

As a result of the conversion, we get a number:

`53`

## Example

And now we added spaces to a number at the beginning and at the end of the string:

`Number(' 5 ');`

After executing the code, extra spaces are removed and as a result we get a number:

`5`

## Example

Let's convert an empty string:

`Number('');`

The code execution result:

`0`

## Example

Now we convert a string containing a letter and a number:

`Number('a5');`

After executing the code, we get the `NaN` value, which indicates an invalid math operation:

`NaN`

## Example

Let's swap a letter and a number in a string:

`Number('5a');`

The result of the code executing will remain the same:

`NaN`

## Example

Now we will convert the string where numbers are separated by a space:

`Number('5 5');`

As a result of the code execution, we will see again that this math operation is invalid:

`NaN`

## Example

Let's convert the boolean `true` value enclosed in a string:

`Number('true');`

After executing the code, we again get `NaN`:

`NaN`

## Example

Now we convert an empty object:

`Number({});`

The code execution result:

`NaN`

## Example

Let's set an empty array as a function parameter:

`Number([]);`

As a result, we get the number `0`:

`0`

## Example

Now we add a number to an array:

`Number([1]);`

The array is converted to a number:

`1`

## Example

Let's convert an array including two digits:

`Number([1, 2]);`

As a result, we will again be informed that this math operation is invalid:

`NaN`

## See also

- the `Number` function
  that converts to a number
- the `parseInt` function
  that extracts an integer from the beginning of a string
- the `parseFloat` function
  that extracts a fractional number from the beginning of a string
- the `String` function
  that converts to a string
- the `Boolean` function
  that converts to a boolean value

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