二进制、十进制互转

十进制整数 转 二进制数组

func number2BinaryStrList(number: Int) -> [String] {
    let binary = String(number, radix: 2)
    let str = String(format: "%07d", Int(binary) ?? 0)
    var strList = [String]()
    for i in str {
        strList.append(String(i))
    }
    return strList
}

举个例子：
print(number2BinaryStrList(number: 12))
输出：["0", "0", "0", "1", "1", "0", "0"]

二进制字符串 转 十进制整数

func binaryStr2Number(str: String) -> Int {
    var sum = 0
    for i in str {
        sum = sum * 2 + (Int((String(i))) ?? 0)
    }
    return sum
}

举个例子：
print(binaryStr2Number(str: "0001100"))
输出：12

二进制数组 转 十进制整数

func binaryStrList2Number(list: [String]) -> Int {
    let reversedList = Array(list.reversed())
    var sum = 0
    for i in 0 ..< reversedList.count {
        let value = pow(2, Double(i)) * (Double(Int(reversedList[i]) ?? 0))
        sum += Int(value)
    }
    return sum
}

举个例子：
print(binaryStrList2Number(list: ["0", "0", "0", "1", "1", "0", "0"]))
输出：12