The code needs to be updated from:
let convert: [String: UInt] = [
"abc": 2, "def": 3, "ghi": 4,
"jkl": 5, "mno": 6, "pqrs": 7,
"tuv": 8, "wxyz": 9
]
to:
let keyMap: [String: UInt] = [
"abc": 2, "def": 3, "ghi": 4,
"jkl": 5, "mno": 6, "pqrs": 7,
"tuv": 8, "wxyz": 9
]
which is consistent with the sample project.