swift 2.0 闭包

//5.闭包 ---其实就是OC中的block

var sumClosure: ((a: Int, b: Int) -> Int )?

//可以省略参数名

var maxClosure: ((Int,Int) -> Int)?

//方式一最原始

//sumClosure = { (a: Int, b: Int) -> Int in

//    return a + b

//}

//方式二 建议使用

//sumClosure = { (a, b) -> Int in

//    return a + b

//}

//方式三 建议使用

//sumClosure = { (a, b) in

//    return a + b

//}

//方式四不建议使用

//sumClosure = { a, b in

//    return a + b

//}

//方式五不建议使用

//sumClosure = { a, b in

//    a + b

//}

//方式六 不建议使用

sumClosure = {

    $0 + $1

}

var result = sumClosure!(a:4,b: 6)

print(result)

//使用typealias起别名

typealias Closure = (Int,Int) -> Int

var diffClosure: Closure! =nil