It marks the string as a verbatim string literal.In C#, a verbatim string is created using a special symbol @. @ is known as a verbatim identifier. If a string contains @ as a prefix followed by double quotes, then compiler identifies that string as a verbatim string and compile that string. The main advantage of @ symbol is to tell the string constructor to ignore escape characters and line breaks.Example Live Demousing System; using System.IO; namespace DemoApplication{    class Program{       static void Main(string[] args){          Console.WriteLine("test string test string");          Console.WriteLine(@"test ... Read More

It is the null-coalescing operator. The null-coalescing operator ?? returns the value of its left-hand operand if it isn't null; otherwise, it evaluates the right-hand operand and returns its result. The ?? operator doesn't evaluate its right-hand operand if the lefthand operand evaluates to non-null.A nullable type can represent a value that can be undefined or from the type's domain. We can use the ?? operator to return an appropriate value when the left operand has a nullable type. If we try to assign a nullable value type to a non-nullable value type without using the ?? operator, we will get ... Read More

Int32 is a type provided by .NET framework whereas int is an alias for Int32 in C# language.Int32 x = 5;int x = 5;So, in use both the above statements will hold a 32bit integer. They compile to the same code, so at execution time there is no difference whatsoever.The only minor difference is Int32 can be only used with System namespace. While validating the type of a value like mentioned above we can use Int32 or int.typeof(int) == typeof(Int32) == typeof(System.Int32)ExampleThe below example shows how an integer is declared using System.Int32. Live Demousing System; namespace DemoApplication{    class Program{     ... Read More

We can store n number of lists of different types in a single generic list by creating a list of list of objects as shown below.List list = new List();Example Live Demousing System; using System.Collections.Generic; namespace MyApplication{    public class Program{       public static void Main(){          List list = new List();          List list1 = new List();          list1.Add(101);          list1.Add(102);          list1.Add(103);          list.Add(list1);          List list2 = new List();          list2.Add("Test1");   ... Read More

The "is" keyword is used to check if an object can be casted to a specific type. The return type of the operation is Boolean.Exampleusing System; namespace DemoApplication{    class Program{       static void Main(){          Employee emp = new PermanentEmployee{             ID = 1,             Name = "Martin"          };          // Returns true as the derived type can be converted to base type.          if (emp is Employee){             ... Read More

As C# is a strongly-typed language, every variable and constant has a pre-defined type. Before using any variable, we must tell the compiler what type of value a variable will store.If we are not sure about the type, then it is handled using dynamic programming. Dynamic programming is supported by the dynamic keyword.The dynamic keyword is used to declare dynamic types. The dynamic types tell the compiler that the object is defined as dynamic and skip type-checking at compiler time, delay type-checking until runtime. All syntaxes are checked and errors are thrown at runtime.Example Live Demousing System; namespace DemoDynamicKeyword{    class ... Read More

Given the task is to find the maximum number of squares having side ‘a’ that can fit inside a give right angle isosceles triangle with base of ‘s’(An isosceles triangle has at least 2 equal sides).Let’s now understand what we have to do using an example:Inputs=5, a=1Output10Explanation − The number of squares in the base can be calculated by dividing s by a and subtracting 1. So the number of squares in base = 5/1 – 1 = 4.Similarly when the bottom 4 squares are placed then we get a new isosceles triangle with base (s-a) and then we repeat ... Read More

Given the task is to find the maximum of segments that can contain the given points.Given an array a1[] with size n1 and two integers A and B are given. From the given array a1[], n1 line segments can be formed with starting and ending points as a1[i] – A and a1[i] + B respectively.Another array a2[] is given with n2 number of points. These points have to be assigned to the line segments such that the number of line segments than have been assigned a point is maximum. Note that a single point can be assigned only once to ... Read More

Given the task is to find the maximum number of removals of given subsequence from a string. A string s is given and we have to find the maximum number of subsequence ‘abc’ that can be removed from the string.Let’s now understand what we have to do using an example:Inputs = ‘dnabcxy’Output1Explanation − Only one subsequence of ‘abc’ can be found in the given string (‘dnabcxy’), therefore the output is 1.Inputs = ‘zcabcxabc’Output2 (‘zcabcxabc’)Approach used in the below program as followsIn Max() function initialize variables i, a, ab, abc with value = 0 and of type int.Loop from i=0 till ... Read More

Given the task is to find the maximum number of people that can be killed with strength P. Consider a row with infinite people and each of them have an index number starting from 1.The strength of the sth person is represented by s2. After killing a person with s strength your strength also decreases by s.Let’s now understand what we have to do using an example −InputP = 20Output3ExplanationStrength of 1st person = 1 * 1 = 1 < 20, therefore 1st person can be killed. Remaining strength = P – 1 = 20 – 1 = 19 Strength ... Read More