如何使用点符号样式编写let子句

基本上这是一个 Select (在大多数情况下)引入了

string[] names = { "Jon", "Mark" };

var query = from name in names
            let length = name.Length
            where length > 3
            select name + ": " + length;

var query = names.Select(name => new { name, length = name.Length })
                 .Where(z => z.length > 3)
                 .Select(z => z.name + ": " z.length);