Swift Set contains()

var languages: Set = ["Swift", "C", "Java"]

// check if languages contains "Swift"
var result = languages.contains("Swift")

print(result)

// Output: true

contains() Syntax

The syntax of the set contains() method is:

set.contains(obj)

Here, set is an object of the set class.

contains() Parameters

The contains() method takes a single parameter:

• obj - element to be checked for its presence in the set

contains() Return Values

The contains() method returns:

• true - if the set contains the specified element
• false - if the set doesn't contain the specified element

Example 1: Swift String contains()

var names: Set = ["Gregory", "Perry", "Nadal"]

// check if names contains "Nadal"
var result = names.contains("Nadal")
print(result)    

// check if message contains "Federer"
result = names.contains("Federer")
print(result)     

Output

true
false

In the above example,

• "Nadal" is present in the set, so the method returns true.
• "Federer" is not present in the set, so the method returns false.

Example 2: Using contains() With if...else

var names: Set = ["Gregory", "Perry", "Nadal"]
var name1 = "Gregory"
var name2 = "gregory"

// true because names contains "Gregory"
if (names.contains(name1)) {

  print( "set contains", name1)
}

else {

  print("set doesn't contain", name1)
}

// contains() is case-sensitive
// false because names doesn't contains "gregory"
if (names.contains(name2)) {

  print( "set contains", name2)
}
else {

  print( "set doesn't contain", name2)
}

Output

set contains Gregory
set doesn't contain gregory