sqrt(newValue) can someone explain why and when to use it ?

Hello Alain:

I don't understand the question.

Do you want to know about the "newValue" keyword, or do you want to know about the "sqrt()" method?

Any who, I will explain both.

• sqrt() is a method or function that will return the square root of a given number.
• newValue is a keyword that's used when passing a new value to computed properties.

For example:

In this explanation I gave to another student in one of the challenges, it explains how to use the keyword "newValue".

• Computed Properties

“In addition to stored properties, classes, structures, and enumerations can define computed properties, which do not actually store a value. Instead, they provide a getter and an optional setter to retrieve and set other properties and values indirectly.”

So we know that a computed property is just a read-only property, where you can’t capture the value and use it somewhere else, it ONLY computes something and displays it (if you can say it like that).

class Temperature {
    var celsius: Float = 0.0
    var fahrenheit: Float {
    get {
        return (celsius * 1.8) + 32.0
        }
    set {
        celsius = (newValue - 32)/1.8 
    }
    }    
}

var temp = Temperature()

temp.fahrenheit = 89 // newValue being passed

In this challenge in order for us to set a value to the celsius property we can use the newValue keyword, this will set the value passed through the fahrenheit computed property

I hope this answer helps you, and if you need a more in depth answer, please let me know.

Good luck