How does this ruby injection magic work?

Question

I saw a ruby code snippet today.

[1,2,3,4,5,6,7].inject(:+)  

=> 28

[1,2,3,4,5,6,7].inject(:*)  
         


        

Answer 1

As you can see in the docs, inject can take a block (like you're familiar with) or a symbol that represents the name of a binary operator. It's a useful shorthand for already-defined ops.