swift无法使用转义序列解码字符串

问题描述：

我的字符串格式为 SO \/ME \/STR \/ING .我想要模拟json进行测试.而当我创建具有以下格式的json时:

I have string on format SO\/ME\/STR\/ING. And I want to have mock json for testing. And when I create json with format like:

let json = """
{ "str": "SO\/ME\/STR\/ING" } // Error: Invalid escape sequence in literal
"""

对于我写的代码，如 SO \\/ME \\/STR \\/ING .但是它解码不正确:

For what I wrote it like SO\\/ME\\/STR\\/ING. But it decodes incorrect:

let json = """
{
    "str": "SO\\/ME\\/STR\\/ING",
}
"""
let jsonData = Data(json.utf8)

let decoder = JSONDecoder()

do {
    let model = try decoder.decode(Model.self, from: jsonData)
    print(model) // Model(str: "SO/ME/STR/ING")
} catch {
    print(error.localizedDescription)
}

如何正确解码?

答

在swift字符串中需要4个反斜杠，以表示 model.str 中的实际反斜杠:

You need 4 backslashes in the swift string to represent an actual backslash in model.str:

let json = """
{
    "str": "\\\\",
}
"""
let jsonData = Data(json.utf8)

let decoder = JSONDecoder()

do {
    let model = try decoder.decode(Model.self, from: jsonData)
    print(model.str) // prints a single backslash
} catch {
    print(error.localizedDescription)
}

JSON 字符串中的反斜杠需要转义，因此在JSON字符串中需要2个反斜杠，但是要在 Swift 字符串文本中编写反斜杠，则需要逃避这两个反斜杠.因此有4个反斜杠.

A backslash in a JSON string needs to be escaped, so you need 2 backslashes in the JSON string, but to write this in a Swift string literal, you need to escape those two backslashes too. Hence the 4 backslashes.

swift无法使用转义序列解码字符串

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