compare items on a list except to yourself-CodePudding

I want to compare items in a list, but I don't want it to be compared to itself. How do I do that? My code:

var students = new List<Student>() {
                new Student(){ Id = 1, Name="Bill"},
                new Student(){ Id = 2, Name="Steve"},
                new Student(){ Id = 3, Name="Ram"},
            };

for (int i=0; i<students.Count(); i  )
{
    for (int x = 0; x < students.Count(); x  )
    {
        Console.WriteLine(students[i].Name   "   --   "   students[x].Name);
    }
}

this code returns...

Bill   --   Bill
Bill   --   Steve
Bill   --   Ram

Steve   --   Bill
Steve   --   Steve
Steve   --   Ram

Ram   --   Bill
Ram   --   Steve
Ram   --   Ram

CodePudding user response：

Maybe you want this:

var students = new List<Student>() {
                new Student(){ Id = 1, Name="Bill"},
                new Student(){ Id = 2, Name="Steve"},
                new Student(){ Id = 3, Name="Ram"},
            };

for (int i=0; i<students.Count(); i  )
{
    for (int x = 0; x < students.Count(); x  )
    {
        if(students[i].Id != students[x].Id)
        {
             Console.WriteLine(students[i].Name   "   --   "   students[x].Name);
        }
    }
}

then you'll get:

Bill   --   Steve
Bill   --   Ram

Steve   --   Bill
Steve   --   Ram

Ram   --   Bill
Ram   --   Steve

CodePudding user response：

You can try with C# Linq query in you first for

for (int i=0; i<students.Count; i  )
    {           
        IEnumerable<Student> compare = students.Where(s => s.Id != students[i].Id);
        
        foreach(var c in compare)
        {
            Console.WriteLine(students[i].Name   " -- "   c.Name);
        }
    }

The IEnumerable class would have all the elements except the one who are you comparing

The Result will be

Bill -- Steve
Bill -- Ram
Steve -- Bill
Steve -- Ram
Ram -- Bill
Ram -- Steve