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: 

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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 ...

}

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:

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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:

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// 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.