问题本身的答案(将其保存为 txt),您可以将浮点数组保存为 JSON 字符串。使用 JSONEncoder/JSONDecoder 对其进行编码和解码应该非常简单。
let values: [Float] = [-.pi, .zero, .pi, 1.5, 2.5]
let encoded = try! JSONEncoder().encode(values)
print(String(data: encoded, encoding: .utf8)!) // "[-3.1415925025939941,0,3.1415925025939941,1.5,2.5]\n"
let decoded = try! JSONDecoder().decode([Float].self, from: encoded) // [-3.141593, 0, 3.141593, 1.5, 2.5]
“但不可能用浮点值初始化数据,不是吗?”
是的,如果绝对可以将浮点数组转换为数据/字节并将其读回。最好保留准确的值,避免转换为字符串:
extension Array {
var bytes: [UInt8] { withUnsafeBytes { .init($0) } }
var data: Data { withUnsafeBytes { .init($0) } }
}
extension ContiguousBytes {
func object<T>() -> T { withUnsafeBytes { $0.load(as: T.self) } }
func objects<T>() -> [T] { withUnsafeBytes { .init($0.bindMemory(to: T.self)) } }
}
let values: [Float] = [-.pi, .zero, .pi, 1.5, 2.5]
let bytes = values.bytes // [218, 15, 73, 192, 0, 0, 0, 0, 218, 15, 73, 64, 0, 0, 192, 63, 0, 0, 32, 64]
let data = values.data // 20 bytes
let minusPI: Float = data.subdata(in: 0..<4).object() // -3.141593
let loaded1: [Float] = bytes.objects() // [-3.141593, 0, 3.141593, 1.5, 2.5]
let loaded2: [Float] = data.objects() // [-3.141593, 0, 3.141593, 1.5, 2.5]