foreach patterns; collection initializers
Write safe foreach loops over arrays, lists, and dictionaries; initialize collections concisely with collection initializer syntax.
Overview
Goal: Iterate safely with foreach and create/populate collections with collection initializers.
- foreach over arrays/lists
- foreach over dictionaries
- List<T> and Dictionary<K,V> initializers
foreach arrays & lists
foreach is simple and safe: it reads items one by one without manual indexing.
using System;
using System.Collections.Generic;
public class Program
{
public static void Main(string[] args)
{
int[] nums = new int[] { 2, 4, 6 };
int sum = 0;
foreach (int n in nums) // no index to manage, safe bounds
{
sum = sum + n;
}
Console.WriteLine("Sum = " + sum);
List<string> names = new List<string>();
names.Add("Ada");
names.Add("Alan");
foreach (string s in names)
{
Console.WriteLine("Hi " + s);
}
}
}
All lessons in this course
- Arrays, slicing, List , Dictionary
- foreach patterns; collection initializers
- LINQ preview: Where, Select, OrderBy, Take/Skip; deferred execution