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iOS Swift Functions and Optionals Optionals Optional Chaining

Posted by Ryan Norton
Ryan Norton
6,218 Points

Why is the "?" suffix needed at all when chaining optionals?

findApt() already returns a nil or optional, so what does adding a "?" change?

1 Answer

Louis Stevens
PLUS
Louis Stevens
Courses Plus Student 749 Points
Louis Stevens
Louis Stevens
Courses Plus Student 749 Points

if let culprit = findApt(“101”) { if let aptNumber = culprit.toInt() { sendNoticeTo(aptNumber: aptNumber) } }

is equivalent to

if let culprit = findApt(“101”)?.toInt() { sendNoticeTo(aptNumber: culprit) }

the '?.' is just a syntax to merge, or chain, the 2 function calls into one line