Please Help Me Intepret This Code SWIFT

Question

display.text = newValue != nil ? \"\\(newValue!)\" : \" \" 

Does the syntax of the code mean, let display.text = newValue, if it does not equal nil

Answer 1

Its a ternary operator. It is use for some condition. If condition is true then it execute the part after ? otherwise the part after :. In your case the condition is if newValue not equals to nil then unwrap it otherwise return empty string.

Answer 2

From the documentation

Ternary Conditional Operator

The ternary conditional operator is a special operator with three parts, which takes the form question ? answer1 : answer2. It is a shortcut for evaluating one of two expressions based on whether question is true or false. If question is true, it evaluates answer1 and returns its value; otherwise, it evaluates answer2 and returns its value.

The ternary conditional operator is shorthand for the code below:

if question {
   answer1 
} else {
   answer2
}

Answer 3

The answers about the ternary operator are correct.

An alternative way to write this would be with the "nil-coalescing operator" ??:

display.text = newValue ?? ""

Which means if the value before ?? Is not nil, use that unwrapped value, else use the value after ??

Answer 4

it means that

if newValue == nil {
    display.text = " "
} else {
    display.text = "(newValue!)"
}

if newValue is not nil, display.text will be (newValue!).

if you want to show newValue's value,

you should write that

if newValue == nil {
    display.text = " "
} else {
    display.text = "\(newValue!)"
}