Swift-闭包中不包含匿名闭包参数

Question

I'm learning the Swift lang with a tutorial.

I'm using this code:

let hasPrefixAndSuffix: (String,String,String) -> Bool
{
  var hasPrefix = $0.hasPrefix($1)
  var hasSuffix = $0.hasSuffix($2)
  return hasPrefix && hasSuffix
}

and I've this error:

Anonymous closure argument not contained in a closure.

Answer 1

You forgot the = which actually assigns that closure to the variable.

let hasPrefixAndSuffix: (String,String,String) -> Bool = {
  var hasPrefix = $0.hasPrefix($1)
  var hasSuffix = $0.hasSuffix($2)
  return hasPrefix && hasSuffix
}