Go - Functions - 3

• Can declare function without name. Called anonymous function.
  
• How client know it needs return value?
  => Because function signature has concrete type description
• Anonymous function can reference variables in enclosing function. 
• Ex
  
• Ex. When inner function got the variable, address is the same
  
• When inner function declare same variable name as outer function, new variable will have new address.
  If we need variable in outer function, need use another variable to point
  
• A function can return another function. 
• A function value can contains state as example