Created
August 12, 2014 16:25
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Example of using dispatch_once() in Swift
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import Foundation | |
var token: dispatch_once_t = 0 | |
func test() { | |
dispatch_once(&token) { | |
println("This is printed only on the first call to test()") | |
} | |
println("This is printed for each call to test()") | |
} | |
for _ in 0..<4 { | |
test() | |
} | |
/* Output: | |
This is printed only on the first call to test() | |
This is printed for each call to test() | |
This is printed for each call to test() | |
This is printed for each call to test() | |
This is printed for each call to test() | |
*/ |
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In Swift 3 something like this: