What is the difference between SequenceType and CollectionType in swift? -


please explain difference between sequencetype, generatortype , collectiontype in swift programming language.

also, if implementing own data structure advantage of using sequencetype, generatortype or collectiontype protocols?

generatortype (iteratorprotocol in swift 3): generators can give next element of sequence, if there no element returns nil. generators encapsulates iteration state , interfaces iteration on sequence.

a generator works providing single method, namely – next(), returns next value underlying sequence.

following classes adopt generatortype protocol:

dictionarygenerator, emptygenerator, more here.

sequencetype (sequence in swift 3): sequence represent series of values. sequence type can iterated for...in loop.

essentially sequence generator factory; knows how make generators sequence.

following classes adopt sequencetype protocol:

nsarray, nsdictionary, nsset , more.

collectiontype (collection in swift 3): collection sequencetype can accessed via subscript , defines startindex , endindex. collection step beyond sequence; individual elements of collection can accessed multiple times.

collectiontype inherits sequencetype

following classes adopt collectiontype protocol:

array, dictionary, set, range , more.

form more information can see this, this, , this


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