C# / .NET - compare strings

In this short article, we would like to show how to compare strings in C#.

Quick solution:

Use Equals() mehod for safety.

Practical example: 

String x = "Hello!";
String y = "Hello!";

if (object.Equals(x, y)) // or: x.Equals(y) when x != null
{
    // Source code when strings are equal here ...
}

Trouble shooting

When we use == operator to compare strings, there is used == operator defined in String class. To compare objects we should use Equals() method.

So, the below source code, comparision returns true value:

String x = "Hello!";
String y = "Hello!";

if (x == y) // unsafe strings comparison !!!
{
    // Source code when strings are equal here ...
}

But, for the changed source code, comparision returns false value:

// using System;
// using System.Text;

object x = new StringBuilder("Hello!").ToString();
object y = new StringBuilder("Hello!").ToString();

Console.WriteLine(x == y);  // False

It is caused by: how x and y variables are stored and what type have.