C# Equals() vs ==

This tutorial will highlight the differences and similarities of the == operator and the Equals() function in C#.

Difference Between the == Operator and the Equals() Function in C#

The == operator is a comparison operator in C#. The == operator compares the reference identities of both operands. On the other hand, the Equals() function compares the contents of two string variables in C#. Typically, both are used for comparing two values. But, they can have different results in different scenarios. The following code example will show a scenario where both the == operator and the Equals() function are true.

using System;

namespace comparison {
  class Program {
    static void Main(string[] args) {
      object var1 = "MMA";
      object var2 = var1;
      if (var1 == var2) {
        Console.WriteLine("== is true");
      }
      if (var1.Equals(var2)) {
        Console.WriteLine("Equals is true");
      }
    }
  }
}

Output:

== is true
Equals is true

In the above code, we initialized an object variable var2 with var2 = var1. It means that both var1 and var2 refer to the same identity in the memory. So, the == operator will result in a true outcome. Since they both have the same contents inside them, the Equals() function will also give true.

Now, we will demonstrate another scenario in which the == operator gives false but the Equals() function returns a true value. This scenario is discussed in the code example below.

using System;

namespace comparison {
  class Program {
    static void Main(string[] args) {
      object var1 = "MMA";
      char[] varc = { 'M', 'M', 'A' };
      object var2 = new string(varc);
      if (var1 == var2) {
        Console.WriteLine("== is true");
      }
      if (var1.Equals(var2)) {
        Console.WriteLine("Equals is true");
      }
    }
  }
}

Output:

Equals is true

In the above code, we created the character array varc and converted it to the object variable var2 by passing varc in the constructor of a string variable. It means that var1 and var2 are both pointing at different identities in the memory. The == operator returns false because it compares the reference identities of var1 and var2. But, the Equals() function returns true because it is comparing the contents of var1 and var2.