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swiftswift4crc16

CRC-16/CCITT in Swift 4

How to get this code working in swift 4:

func crc16ccitt(data: [UInt8], seed: UInt16 = 0x1d0f, final: UInt16 = 0xffff) -> UInt16 {
    var crc = seed
    data.forEach { (byte) in
        crc ^= UInt32(byte) << 8
        (0..<8).forEach({ _ in
            crc = (crc & UInt32(0x8000)) != 0 ? (crc << 1) ^ 0x1021 : crc << 1
        })
    }
    return UInt16(crc & final)
}
print(crc16ccitt(data: "Karim".utf8.map{$0}) == 0x792C)

I get 2 errors:

"Binary operator'^=' cannot be applied to operands of type 'UInt16' and 'UInt32'

"Binary operator'&' cannot be applied to operands of type 'UInt16' and 'UInt32'
Solution

  • You can use UInt16(byte) instead of UInt32(byte)