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// Swift 4 builtin data types:
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//
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// * Int or UInt (Int32, Int64, UInt32, UInt64)
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// * Float
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// * Double
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// * Bool
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// * String
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// * Character
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// * Optional − a variable that can hold either a value or no value.
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// * Tuples
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//
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// | -------|-------------------|-----------------------------------------------|
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// | Type | Typical Bit Width| Typical Range |
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// | -------|-------------------|-----------------------------------------------|
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// | Int8 | 1byte | -127 to 127 |
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// | UInt8 | 1byte | 0 to 255 |
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// | Int32 | 4bytes | -2147483648 to 2147483647 |
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// | UInt32 | 4bytes | 0 to 4294967295 |
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// | Int64 | 8bytes | -9223372036854775808 to 9223372036854775807 |
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// | UInt64 | 8bytes | 0 to 18446744073709551615 |
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// | Float | 4bytes | 1.2E-38 to 3.4E+38 (~6 digits) |
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// | Double | 8bytes | 2.3E-308 to 1.7E+308 (~15 digits) |
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// | -------|-------------------|-----------------------------------------------|
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// Type Aliases:
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//
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typealias Feet = Int
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var distance: Feet = 100
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print(distance)
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// Type inference:
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//
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// varA is inferred to be of type Int
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var varA = 42
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print(varA)
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//
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// varB is inferred to be of type Double
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var varB = 3.14159
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print(varB)
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//
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// varC is also inferred to be of type Double
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var varC = 3 + 0.14159
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print(varC)
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