If i have two arrays & i want to compare their indexes, for ex:
let var a1 = ["1", "2", "3"]
let var a2 = ["3", "2", "3"]
And i wanted to print something to say which index wasn't the same, such as:
if a1[0] != a2[0] && a1[1] == a2[1] && a1[2] == a2[2]{
print("Index 0 is not the same.")
Would i have to write 7 more of those statements to show all 8 possibilities of all correct/all wrong/index 1&1 wrong, etc?
Thank you!
You can get all indexes like this:
let diffIndex = zip(a1, a2).enumerated().filter {$1.0 != $1.1}.map {$0.offset}
Explanation:
zip produces a sequence of pairsenumerated() adds an index to the sequencefilter keeps only pairs with different valuesmap harvests the index, and builds the sequence of results.Running this on
let a1 = ["1", "2", "3", "4"]
let a2 = ["3", "2", "3", "5"]
This produces a sequence [0, 3]
Try this
let a1 = ["1", "2", "3"]
let a2 = ["3", "2", "3"]
let result = zip(a1, a2).map({ $0 == $1 }).reduce(true, {$0 && $1})
Use a for loop:
for i in 0..<a1.length {
if a1[i] != a2[i] {
print("Index \(i) is not the same")
}
}
Generally if you find yourself repeating the same code but with different numbers, you can substitute it with a for loop.
a1 and a2 elements, as long as != operator can be applied.Surely you could do something like this:
let a1 = ["1", "2", "3"]
let a2 = ["3", "2", "3"]
var compareResult : [String] = [String]()
if a1.count == a2.count { // Need to check they have same length
for count in 0..<a1.count {
let result : String = a1[count] == a2[count] ? "MATCH" : "MISMATCH"
compareResult.append(result)
}
print(compareResult)
// Do something more interesting with compare result...
}
