Learning Functional Programming in Go

Associativity rule

“If you combine several more values, the order in which you combine does not matter”

( 1 + 2 ) + 3 == 1 + ( 2 + 3 )   // left and right associativity

So, if we have 1 + 2 + 3 + 4, we can transform that into ( 1 + 2 ) + ( 3 + 4 ).

Note that associativity works for addition and multiplication and string concatenation, but not for subtraction and division.