How to determine if one array contains all elements of another array in Swift?
Instead of iterating through arrays and doing filtering yourself, you can use NSSet
to do all the work for you.
var list:Array<Int> = [1,2,3,4,5]
var findList:Array<Int> = [1,3,5]
let listSet = NSSet(array: list)
let findListSet = NSSet(array: findList)
let allElemtsEqual = findListSet.isSubsetOfSet(otherSet: listSet)
NSSet
is a lot faster than arrays at checking if it contains any object. In fact it's what it's designed for.
Edit: Using Swift's built-in Set
.
let list = [1,2,3,4,5]
let findList = [1,3,5]
let listSet = Set(list)
let findListSet = Set(findList)
//**Swift 4.2 and Above**
let allElemsContained = findListSet.isSubset(of: listSet)
//below versions
//let allElemsContained = findListSet.isSubsetOf(listSet)
allSatisfy
seems to be what you want, assuming you can't conform your elements to Hashable
and use the set intersection approach others have mentioned:
let containsAll = subArray.allSatisfy(largerArray.contains)