Comparison operators (C# reference)
The < (less than), > (greater than), <= (less than or equal), and >= (greater than or equal) comparison, also known as relational, operators compare their operands. Those operators are supported by all integral and floating-point numeric types.
Note
For the ==, <, >, <=, and >= operators, if any of the operands is not a number (Double.NaN or Single.NaN), the result of operation is false. That means that the NaN value is neither greater than, less than, nor equal to any other double (or float) value, including NaN. For more information and examples, see the Double.NaN or Single.NaN reference article.
The char type also supports comparison operators. In the case of char operands, the corresponding character codes are compared.
Enumeration types also support comparison operators. For operands of the same enum type, the corresponding values of the underlying integral type are compared.
The == and != operators check if their operands are equal or not.
Less than operator <
The < operator returns true if its left-hand operand is less than its right-hand operand, false otherwise:
Console.WriteLine(7.0 < 5.1); // output: False
Console.WriteLine(5.1 < 5.1); // output: False
Console.WriteLine(0.0 < 5.1); // output: True
Console.WriteLine(double.NaN < 5.1); // output: False
Console.WriteLine(double.NaN >= 5.1); // output: False
Greater than operator >
The > operator returns true if its left-hand operand is greater than its right-hand operand, false otherwise:
Console.WriteLine(7.0 > 5.1); // output: True
Console.WriteLine(5.1 > 5.1); // output: False
Console.WriteLine(0.0 > 5.1); // output: False
Console.WriteLine(double.NaN > 5.1); // output: False
Console.WriteLine(double.NaN <= 5.1); // output: False
Less than or equal operator <=
The <= operator returns true if its left-hand operand is less than or equal to its right-hand operand, false otherwise:
Console.WriteLine(7.0 <= 5.1); // output: False
Console.WriteLine(5.1 <= 5.1); // output: True
Console.WriteLine(0.0 <= 5.1); // output: True
Console.WriteLine(double.NaN > 5.1); // output: False
Console.WriteLine(double.NaN <= 5.1); // output: False
Greater than or equal operator >=
The >= operator returns true if its left-hand operand is greater than or equal to its right-hand operand, false otherwise:
Console.WriteLine(7.0 >= 5.1); // output: True
Console.WriteLine(5.1 >= 5.1); // output: True
Console.WriteLine(0.0 >= 5.1); // output: False
Console.WriteLine(double.NaN < 5.1); // output: False
Console.WriteLine(double.NaN >= 5.1); // output: False
Operator overloadability
A user-defined type can overload the <, >, <=, and >= operators.
If a type overloads one of the < or > operators, it must overload both < and >. If a type overloads one of the <= or >= operators, it must overload both <= and >=.
C# language specification
For more information, see the Relational and type-testing operators section of the C# language specification.
