/// Question2 Refactor the code below so that the nested if statements 
/// are reduced as much as possible.
/// Attempt to failfast as much as possible, 
/// so that all checks do not need to run if any validation has failed.


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace InterviewQuestions
{
    public interface ISuccessChecker
    {
        bool DidSucceed();
    }
    public class Question2
    {
        ISuccessChecker _initializationChecker;
        ISuccessChecker _nullChecker;
        ISuccessChecker _dataEntryValidation;
        ISuccessChecker _databaseValiator;

        public void Checker(ISuccessChecker initializationChecker, ISuccessChecker nullChecker,
            ISuccessChecker dataEntryChecker, ISuccessChecker databaseValidator)
        {
            _initializationChecker = initializationChecker;
            // if(initializationChecker.DidSucceed() == false) {
            //     return "Entry did not pass initial validation"
            // }
            _nullChecker = nullChecker;
            _dataEntryValidation = dataEntryChecker;
            _databaseValiator = databaseValidator;
        }

        public string GetResult()
        {
            string resultToReturnToUser = string.Empty;

            if (_initializationChecker.DidSucceed())
            {
                if (_nullChecker.DidSucceed())
                {
                    if (_dataEntryValidation.DidSucceed())
                    {
                        if (_databaseValiator.DidSucceed())
                        {
                            resultToReturnToUser = "validated";
                        }
                        else
                        {
                            resultToReturnToUser = "Could not validate database";
                        }
                    }

                    else
                    {
                        resultToReturnToUser = "Could not validate data entry";
                    }
                }

                else
                {
                    resultToReturnToUser = "Could not validate nulls";
                }

            }

            else
            {
                resultToReturnToUser = "Entry did not pass initial validation";
            }

            return resultToReturnToUser;
        }

        void Test(){
            Question2 data = new Question2();
            _initializationChecker.DidSucceed = true;
            data.Checker(_initializationChecker, _nullChecker, _dataEntryValidation, _databaseValiator);
        }
        public static void Main(string[] args)
        {
            //var initializationChecker = new ISuccessChecker;
           
            Console.WriteLine("Hello World!");

        }
    }

    public class Test : ISuccessChecker
    {
        public bool initializationChecker()
        {
            return true;
        }
       
    }
     
}
 
by

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Read inputs from stdin

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using System;
 
namespace Sample
{
  class Test
    {
      public static void Main(string[] args)
       {
         string name;
         name = Console.ReadLine();
         Console.WriteLine("Hello {0} ", name);
	}
     }
}

About C Sharp

C# is a general purpose object-oriented programming language by Microsoft. Though initially it was developed as part of .net but later it was approved by ECMA and ISO standards.

You can use C# to create variety of applications, like web, windows, mobile, console applications and much more using Visual studio.

Syntax help

Data types

Data TypeDescriptionRangesize
intTo store integers-2,147,483,648 to 2,147,483,6474 bytes
doubleto store large floating point numbers with decimalscan store 15 decimal digits8 bytes
floatto store floating point numbers with decimalscan store upto 7 decimal digits4 bytes
charto store single characters-2 bytes
stringto stores text-2 bytes per character
boolto stores either true or false-1 bit

Variables

Syntax

datatype variable-name = value;

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition or set of few conditions IF-ELSE is used.

if(conditional-expression) {
   // code
} 
else {
   // code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression) {    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
...    
    
default:     
 // code to be executed when all the above cases are not matched;    
} 

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement) {
  // code  
} 

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while(condition) {
 // code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {
  // code 
} while (condition);

Arrays

Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.

Syntax

data-type[] array-name;

Methods

Method is a set of statements which gets executed only when they are called. Call the method name in the main function to execute the method.

Syntax

static void method-name() 
{
  // code to be executed
}