#       
## Overview
The **`isNormal` property** of an  instance of type double in Swift is used to check if the instance is normal. A **normal** value is a finite number that uses full precision available to it.
## Syntax
```swift
Double.isNormal
```
## Return value
The value returned is a boolean. It is `true` if the value is normal. Otherwise, `false` is returned.
## Code example


// create double values
let x1 = 34.444
let x2 = 0.0
let x3 = 1.2
let x4 = Double.infinity
let x5 = -0.555

// check if normal
print(x1.isNormal)  // true
print(x2.isNormal)  // false
print(x3.isNormal)  // true
print(x4.isNormal)  // false
print(x5.isNormal)  // true

## Explanation
* **Lines 2-6**: We create some double values.
* **Lines 9-13**: We check to see if the values are normal and print the results to the console.

What is the Double.isNormal property in Swift?

Double.isNormal checks if a double value is finite and uses full precision, returning true if so.