C# nested dictionaries | 易学教程

问题

What is wrong with my syntax? I want to be able to get the value "Genesis" with this info["Gen"]["name"]

    public var info = new Dictionary<string, Dictionary<string, string>> {
    {"Gen", new Dictionary<string, string> {
    {"name", "Genesis"},
    {"chapters", "50"},
    {"before", ""},
    {"after", "Exod"}
    }},
    {"Exod", new Dictionary<string, string> {
    {"name", "Exodus"},
    {"chapters", "40"},
    {"before", "Gen"},
    {"after", "Lev"}
    }}};

回答1:

You cannot define a class field using var.

Change var to Dictionary<string, Dictionary<string, string>>:

public Dictionary<string, Dictionary<string, string>> info =
    new Dictionary<string, Dictionary<string, string>>
    {
        {
            "Gen",
            new Dictionary<string, string>
            {
                {"name", "Genesis"},
                {"chapters", "50"},
                {"before", ""},
                {"after", "Exod"}
            }
        },
        {
            "Exod",
            new Dictionary<string, string>
            {
                {"name", "Exodus"},
                {"chapters", "40"},
                {"before", "Gen"},
                {"after", "Lev"}
            }
        }
    };

See here for more information about var keyword and its usage.

回答2:

From MSDN;

var can only be used when a local variable is declared and initialized in the same statement; the variable cannot be initialized to null, or to a method group or an anonymous function.

var cannot be used on fields at class scope.

Variables declared by using var cannot be used in the initialization expression.

Just change your var to Dictionary<string, Dictionary<string, string>>. Like;

public Dictionary<string, Dictionary<string, string>> info =
    new Dictionary<string, Dictionary<string, string>>{}

来源：https://stackoverflow.com/questions/15501202/c-sharp-nested-dictionaries

标签

dictionary

nested