Is there a programming language where the static data type is optional?

Question

I'm thinking something where the following two are equivalent:

 int [] array = { 1,2,3,4 }
 foreach( int i in array ) {
    print i 
 }


 array = { 1,2,3,4 }
 foreach( i in array ) {
     print i 
 }

Answer 1

Yes, languages that have type inference work this way. The code is statically typed, but the compiler can figure out that if you write { 1,2,3,4 }, then anything you assign that to, or call with that, is of type int[]. It saves a lot of (finger) typing.

Answer 2

C# allows you to use the var keyword in declarations to infer the type from the right hand side of the assignment.