#1,215 – C# 6.0 – New Syntax for Dictionary Initializers

Prior to C# 6.0, you could initialize a Dictionary object with a collection initializer as follows:

            // Initialization with collection initializer
            Dictionary<string, int> guys = new Dictionary<string, int> {
                {"Galileo", 1564},
                {"Magellan", 1480},
                {"Voltaire", 1694},
                {"Kepler", 1571},
                {"Keaton", 1895}
            };

In C# 6.0, the following syntax will also work:

            // Initialization with new dictionary initializer
            Dictionary<string, int> guys = new Dictionary<string, int>
            {
                ["Galileo"] = 1564,
                ["Magellan"] = 1480,
                ["Voltaire"] = 1694,
                ["Kepler"] = 1571,
                ["Keaton"] = 1895
            };

Note that as of 29 Oct, 2014, this feature is not enabled in the current Visual Studio 2014 CTP.