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Comment by b0sk | Hacker News Reader

Right. I think Rust was the first to propose “?” operator as a syntactic sugar to Result and Option monads. (i am not 100% though)

ref: https://m4rw3r.github.io/rust-questionmark-operator

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Ruby got the safe navigation operator (&. to safely call methods on a nil-able value) in 2015, with Ruby 2.3, and credits "C#, Groovy and Swift" for inspiration there. So while it isn't exactly "?" (I think Groovy does use the ?), the semantics are close enough IMO.

Ref: https://www.ruby-lang.org/en/news/2015/12/25/ruby-2-3-0-rele...

Yes, Groovy has used '?' in various forms for some years now as well:

https://www.logicbig.com/tutorials/misc/groovy/safe-navigati...

https://www.logicbig.com/tutorials/misc/groovy/elvis-operato...

C# added this operator in 2014 with C# 6 ( and the simultaneous release of VS2015.)

https://docs.microsoft.com/en-us/dotnet/csharp/whats-new/csh...

https://docs.microsoft.com/en-us/archive/msdn-magazine/2014/...

Roslyn compiler, also supporting this operator, was released earlier in the same year, too.

C#'s Null-Conditional operator isn't the same as Rust's Try operator. The Try operator will early return from a function, while the Null-Conditional operator conditionally executes the rest of the expression if the receiver isn't null, or else evaluates to null. The equivalent in Rust is the `and_then` method.

C# also has a Null-Coalescing operator (`??`) which behaves like Rust's `unwrap_or` method.

I think Kotlin may have had it before 2015.

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