Please explain
var numerator = ingredient.num ?? 1
Why we have to assign 1 to ingredient.num if ingredient.num is nil?
Thanks
Reason has been found; you can not have 0/denominator.
That’s not quite correct. If you look at Recipe.swift…
struct Ingredient: Identifiable, Decodable {
var id: UUID?
var name: String
var num: Int?
var denom: Int?
var unit: String?
}
…you will see that num is declared as Optional so if num is nil then use nil coalescing to provide the value 1.
why 1, not 0
AI got this answer
In the code snippet you provided, denominator is assigned the value of ingredient.denom if it is not null ( ?? is the null-coalescing operator). Otherwise, it is assigned the value 1 .
The reason 1 is used as the default value instead of 0 is because 0 as a denominator would cause a division by zero error, which is generally undesirable in most cases. To avoid this error, a non-zero default value such as 1 is commonly chosen. This ensures that the division operation is always well-defined and avoids potential runtime errors.
By using 1 as the default denominator, if ingredient.denom is null , the division operation will effectively be a division by 1 , which is equivalent to simply using the numerator value alone. This can be useful in various scenarios where a default value is needed, but dividing by zero is not desired.
In the case of the denominator the value can’t be zero since that would cause a division by zero and a crash.
In the example you provided we are talking about num which is the numerator (the value that denominator is divided into). We set it to 1 using the nil coalescing operator because the you can’t have an ingredient quantity of 0.
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I almost forgot all about fractions. Thanks