SwiftUI ForEach, conditionals and showing one result of many - swiftui

Question

I have an interesting looping and conditional problem that I’m having trouble solving.
struct ForEachLoopTesting: View {
let start = ["a", "b", "c", "a"]
let this = ["a", "b"]
var body: some View {
VStack {
ForEach(start, id:\.self) { test1 in
ForEach(start, id:\.self) { test2 in
if [test1, test2] == this {
Text("true") // this prints twice…how can I get to print only once?
}
}
}
}
}
}
Any ideas on how I can show the first result of the multiple results that meet the condition? Or maybe I'm approaching this wrong and there's a better way?

Answer 1

you could try something like this approach, without using the ForEach loop (because they require the entries to be unique):
struct ForEachLoopTesting: View {
let start = ["a", "b", "c", "a"]
let this = ["a", "b"]
var body: some View {
if startContains(this) {
Text("yes start contains this")
} else {
Text("no start does not contain this")
}
}
func startContains(_ this: [String]) -> Bool {
var result = false
outerLoop: for test1 in start {
for test2 in start {
if ([test1, test2] == this) {
result = true
break outerLoop
}
}
}
return result
}
// alternative
func startContains2(_ this: [String]) -> Bool {
for test in this {
if !start.contains(test) {
return false
}
}
return true
}
}

Answer 2

You should not manage this inside the body of the view. Instead, it could be easier to leave the logic to a supporting function and ask SwiftUI to render the final result on the screen.
The example below separates the logic from the view's body:
struct ForEachLoopTesting: View {
let start = ["a", "b", "c", "a"]
let this = ["a", "b"]
// Supporting function
private var merged: [[String]] {
var merged = [[String]]()
start.forEach { test1 in
start.forEach { test2 in
let item = [test1, test2]
// Check for both: the condition and that
// the pair is not yet included in the array
if item == this && !merged.contains(item) {
merged.append([test1, test2])
}
}
}
return merged
}
var body: some View {
VStack {
// Read and show the final result
ForEach(merged, id:\.self) { item in
HStack {
Text(item[0])
Text(item[1])
Text("true")
}
}
}
}
}