var someDict:[Int:String] = [1:"One", 2:"Two", 3:"Three"] var oldVal = someDict[1] someDict[1] = "One 新的值" var someVar = someDict[1] print( "key = 1 旧的值 \(oldVal)" ) print( "key = 1 的值为 \(someVar)" ) print( "key = 2 的值为 \(someDict[2])" ) print( "key = 3 的值为 \(someDict[3])" )