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How to do this in LINQ?

开发者 https://www.devze.com 2023-01-26 09:51 出处:网络
I can\'t express what I want to do. Please help. Considering my code below开发者_JS百科: void Main()

I can't express what I want to do. Please help. Considering my code below开发者_JS百科:

void Main()
{
    List<Person> person = new List<Person>
    {
        new Person { Name = "Maria Anders", Age = 21 },
        new Person { Name = "Ana Trujillo", Age = 55 },
        new Person { Name = "Thomas Hardy", Age = 40 },
        new Person { Name = "Laurence Lebihan", Age = 18 },
        new Person { Name = "Victoria Ashworth", Age = 16 },
        new Person { Name = "Ann Devon", Age = 12 }
    };

    person.Select(x => new { x.Name, x.Age }).Dump();
}

class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
}

I want to print the Name | Age | Status of a person.

Status is a derived column. Where it should have a value of either "Adult" if the person's age is >= 18, otherwise "Under age".


First you need to add a property named Status to class Person.

class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
    public string Status 
    {
       get { return Age >= 18 ? "Adult" : "Under age"; }
    }
    public override string ToString()
    {
       return string.Format("{0}|{1}|{2}",Name,Age,Status);
    }
}

then you can loop into the list of person to do your action:

foreach(Person p in persons)
{
    Console.WriteLine(p);
}
//Or
persons.ForEach( p => Console.WriteLine(p) );

The reason of adding Status property and overriding ToString method is to put the logic in one place. Otherwise, suppose some day, you need to change "Under age" to "Nonage", you won't need to change the strings everywhere but only one place in your Person class.


How about:

person.Select(p =>
  String.Format("{0} | {1} | {2}",
  p.Name, p.Age, p.Age >= 18 ? "Adult" : "Under age"))
  .Dump();

Then somewhere else:

static void Dump(this IEnumerable<string> ss)
{
    foreach(var s in ss)
    {
        Console.WriteLine(s);
    }
}


var y = person.Select(x => new { x.Name, x.Age, Status = x.Age > 18 ? "Adult" : "Minor" });


Its simple.. sb.ToString() will give you what you want.

    StringBuilder sb = new StringBuilder();

        foreach(Person p in person)
        {
        string status = p.Age >= 18 ? "Adult" : "Not Adult";

        sb.AppendLine(String.Format("{0} {1} {2}",p.Name,p.Age.ToString(),status));
        sb.AppendLine(Environment.NewLine);

        }


person.Select(x => new { x.Name, x.Age ,Status = (x.Age>=18) ? "Adult":"Under Age"})


try:

person.Select(x => new {Name =  x.Name, Age = x.Age, Status = ((x.Age>=18) ? "Adult" :"Child") }); ;
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