CODEWITHSUNDEEP
swift
Hyun Kim
Hyun Kim

Reputation: 9

Please Help Me Intepret This Code SWIFT

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

Does the syntax of the code mean, let display.text = newValue, if it does not equal nil let it be an optional of newValue as a string or " ". This interpretation is a guess, any help that can be provided will be appreciated

Thank you

Upvotes: 0

Views: 95

Answers (4)

Abizern
Abizern

Reputation: 150605

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 ??

Upvotes: 0

Archie
Archie

Reputation: 150

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!)"
}

Upvotes: 0

vadian
vadian

Reputation: 285079

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
}

Upvotes: 1

Muhammad Zeeshan
Muhammad Zeeshan

Reputation: 2451

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.

Upvotes: 1

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