コード例 #1
0
ファイル: Program.cs プロジェクト: wawer1/CSharpTraining
        static void Main(string[] args)
        {
            var numbers = new List <int>()
            {
                1, 2, 3, 4
            };              //deklaracja listy z wartościami

            numbers.Add(1); //dodanie elementu do listy
            numbers.AddRange(new int[3] {
                5, 6, 7
            });                                       //dodanie tablicy do listy

            foreach (int num in numbers)
            {
                Console.WriteLine(num);
            }

            Console.WriteLine();

            //IndexOf()
            var pos = numbers.IndexOf(1); //1. wystąpienie wartości

            Console.WriteLine(pos);
            var pos2 = numbers.LastIndexOf(1); //ostatnie wystąpienie wartości

            Console.WriteLine(pos2);

            Console.WriteLine();

            //Count - długość listy
            Console.WriteLine("Count: " + numbers.Count);


            //Remove //usunięcie pierwszego wystąpienia danej wartości
            //numbers.Remove(1);

            /*foreach (int num in numbers)  // NIE WOLNO UŻYWAC FOREACH DO USUWANIA EL. Z LISTY
             * {
             *  if(num ==1)
             *  numbers.Remove(num);
             *
             * }*/

            Console.WriteLine();

            for (var i = 0; i < numbers.Count; i++)
            {
                if (numbers[i] == 1)
                {
                    numbers.Remove(numbers[i]);
                }
            }

            foreach (int num in numbers)
            {
                Console.WriteLine(num);
            }

            //Clear - usuwa wszystkie elementy z listy
            numbers.Clear();
            Console.WriteLine("Count: " + numbers.Count);
        }
コード例 #2
0
        static void Main(string[] args)
        {
            var numbers = new List <int>()
            {
                1, 2, 3, 4
            };

            // Add() --> it adds an object to a list
            numbers.Add(1);


            // AddRange() --> add another list or array of lists
            numbers.AddRange(new int[3] {
                5, 6, 7
            });

            foreach (var n in numbers)
            {
                Console.WriteLine(n);
            }


            /*
             * IndexOf()
             *  - returns the index of a given object or '-1' if object doesn't exist
             *  - it searches from the beginning of the List
             *  - LastIndexOf searches from the end of the List
             */
            Console.WriteLine("Index of 1: " + numbers.IndexOf(1));
            Console.WriteLine("Last Index of 1: " + numbers.LastIndexOf(1));


            // Count() --> returns the number of objects in the list
            Console.WriteLine("Count: " + numbers.Count());


            /*
             * Remove()
             *  - cannot modify a collection from within a 'foreach' group
             */
            for (int i = 0; i < numbers.Count; i++)
            {
                if (numbers[i] == 1)
                {
                    numbers.Remove(numbers[i]);
                }
            }
            foreach (var number in numbers)
            {
                Console.WriteLine(number);
            }
            // we removed both '1s' from the list


            // Clear() --> removes all items from the List
            numbers.Clear();
            Console.WriteLine("Count of numbers: " + numbers.Count());



            // Exercises
            var exercises = new Exercises();

            //exercises.Number1();
            //exercises.Number2();
            //exercises.Number3();
            //exercises.Number4();
            exercises.Number5();
        }
コード例 #3
0
        static void Main(string[] args)
        {
            List <int> listOfNumbers = new List <int>()
            {
                1, 2, 3, 4
            };

            // Add and AddRange
            listOfNumbers.Add(5);
            listOfNumbers.AddRange(new int[] { 6, 7, 8 });

            foreach (int number in listOfNumbers)
            {
                Console.Write(number + " ");
            }
            Console.WriteLine();

            // IndexOf and LastIndexOf
            int n = listOfNumbers.IndexOf(1);

            Console.WriteLine("Index of 1: " + n);
            int n2 = listOfNumbers.LastIndexOf(3);

            Console.WriteLine("Last index of 3: " + n2);

            // Count
            Console.WriteLine("Count of elements: " + listOfNumbers.Count);

            // Remove
            listOfNumbers.Remove(1);

            foreach (int num in listOfNumbers)
            {
                Console.Write(num + " ");
            }
            Console.WriteLine();

            listOfNumbers.RemoveAt(0);
            foreach (int num in listOfNumbers)
            {
                Console.Write(num + " ");
            }
            Console.WriteLine();

            for (int i = 0; i < listOfNumbers.Count; i++)
            {
                if (listOfNumbers[i] == 6)
                {
                    listOfNumbers.RemoveAt(i);
                }
            }

            foreach (int num in listOfNumbers)
            {
                Console.Write(num + " ");
            }
            Console.WriteLine();

            listOfNumbers.Clear();
            foreach (int num in listOfNumbers)
            {
                Console.Write(num + " ");
            }
            Console.WriteLine(listOfNumbers.Count);
        }
コード例 #4
0
        static void Main(string[] args)
        {
            // Lists are dynamic, whereas Arrays are static
            // Lists are a generic type

            // Example List

            var numbers = new List <int>()
            {
                1, 2, 3, 4
            };

            numbers.Add(1);
            numbers.AddRange(new int[3] {
                5, 6, 7
            });

            foreach (var number in numbers)
            {
                Console.WriteLine(number);
            }

            // IndexOf()
            Console.WriteLine("Index of 1: " + numbers.IndexOf(1));

            // LastIndexOf()
            Console.WriteLine("Last Index of 1: " + numbers.LastIndexOf(1));

            // Count
            Console.WriteLine("Count: " + numbers.Count);

            // Remove
            // foreach throws error, so use regular for loop
            //foreach (var number in numbers)
            //{
            //    if (number == 1)
            //        numbers.Remove(number);
            //}
            for (var i = 0; i < numbers.Count; i++)
            {
                if (numbers[i] == 1)
                {
                    numbers.Remove(numbers[i]);
                }
            }

            foreach (var number in numbers)
            {
                Console.WriteLine(number);
            }

            // Clear()
            numbers.Clear();
            Console.WriteLine("Count: " + numbers.Count);

            Console.WriteLine();
            // Useful List methods
            // Add()
            // AddRange()
            // Remove()
            // RemoveAll()
            // IndexOf()
            // Contains()
            // Count
        }