How to count occurrences of an element in a Swift / array?

Question

How to count a number of time in array there are "Yes" ? In swift

["julien: Yes","elie: Yes", "Mark: No", "Jean: Yes"]

For exemple here there are 3 times Thanks ;)

What have you tried so far? However, I do not think that this is some smart data structure. — Hermann Klecker
– Hermann Klecker, Commented Dec 14, 2015 at 12:17
Possible duplicate of How to count occurrences of an element in a Swift array? — Armin
– Armin, Commented Dec 14, 2015 at 12:21
This can be done very simple with enumeration. Or do you want to do this in some smart functional-style way? — kelin
– kelin, Commented Dec 14, 2015 at 12:24
Possible duplicate of Count number of items in an array with a specific property value — Nicolai Henriksen
– Nicolai Henriksen, Commented Mar 7, 2017 at 20:41

Liam · Accepted Answer · 2015-12-14 12:40:37Z

4

How about something like this?

//: Playground - noun: a place where people can play

import UIKit

let array = ["julien: Yes","elie: Yes", "Mark: No", "Jean: Yes"]
let results = array.map({ $0.lowercaseString.containsString("yes") })
let count = results.filter({ $0 == true }).count
count // 3

You can also make it a one liner:

let count = array.filter({ $0.lowercaseString.containsString("yes") }).count

Note: I also added a check for case sensitivity just incase the data source was inconsistent

edited Dec 14, 2015 at 12:40

answered Dec 14, 2015 at 12:22

Liam

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chiarotto.alessandro · Accepted Answer · 2015-12-14 12:20:16Z

2

let a = ["julien: Yes","elie: Yes", "Mark: No", "Jean: Yes"]
let filtered = a.filter { (str) -> Bool in
    return str.containsString("Yes")
}
print(filtered.count)

answered Dec 14, 2015 at 12:20

chiarotto.alessandro

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Lukas Kukacka · Accepted Answer · 2015-12-14 12:27:06Z

2

let array = ["julien: Yes","elie: Yes", "Mark: No", "Jean: Yes"]
let count = array.reduce(0) { $0 + ($1.containsString("Yes") ? 1 : 0) }
count // 3

answered Dec 14, 2015 at 12:27

Lukas Kukacka

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Narayana Rao Routhu · Accepted Answer · 2015-12-14 12:48:37Z

1

You can use NSPredicate to get required output like below

var arrayTemp = NSMutableArray(objects: "julien: Yes","elie: YES", "elie: NO", "Jean: Yes")
var predicate = NSPredicate(format: "self contains[cd] %@", "Yes")
arrayTemp.filterUsingPredicate(predicate)
print("COUNT===\(arrayTemp.count)")// 3

answered Dec 14, 2015 at 12:48

Narayana Rao Routhu

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