Are there languages without “null”?

Question

There are many people who think that the concept of the special value null (as it is used in lanuages like C, Java, C#, Perl, Javascript, SQL etc.) is a bad idea. T

Answer 1

Here's an incomplete list of languages that are null-safe in the sense you described:

• C# 8 will have nullable reference types.
• Prolog. A logical variable stands for "anything at all". There is no concept of "null" or "undefined".
• Pony (pre-1.0.0). Uses union type where one of the types is None.
• Crystal (in alpha stage): Does have nil, but prevents all null pointer exceptions at compile-time.
• Kotlin (2015): Has optional types with ? syntax.
• Swift (2014): Has optional types with ? syntax.
• Hack (2014): Has optional types with ? syntax.
• TypeScript (2012): Has union types that can have undefined or null as a variant.
• Elm (2012): Has union type Maybe.
• Ceylon (2011): Has optional types with ? syntax.
• Rust (2010): Has optional type Option.
• Fantom (2005): Has optional types with ? syntax.
• F# (2005): Has union type Option.
• Nice (2003): Has optional types with ? syntax.
• Netlogo (1999) has no type null
• OCaml (1996): Has union type option.
• Haskell (1990): Has union type Maybe.
• Standard ML (1990): Has union type option.
• Tcl (1988)
• Erlang (1986)

Feel free to complement the list. The year represents the first appearance according to Wikipedia.