What is the difference between operators ? and ?? in c#

The

? and ?? operators are conditional operators used to select values. The ? operator throws an exception if either operand is null, the ?? operator handles null values ​​safely and returns the right operand if the left operand is null.

The difference between operators ? and ?? in C

#The operators ? and ?? in C# are both Is a conditional operator used to select values ​​under specific conditions. However, their main difference is the mechanism for handling null values:

? operator (ternary conditional operator)

• Syntax: condition ? value_if_true : value_if_false
• is used to return a value when the condition is true, otherwise return another value.
• If the condition is true, return value_if_true, otherwise return value_if_false.
• If value_if_true or value_if_false is null, a NullReferenceException is thrown.

Example:

<code class="csharp">int? nullableValue = null;
string result = nullableValue ?? "Default value";  // result = "Default value"</code>

?? Operator (null coalescing operator)

• Syntax ：leftOperand ?? rightOperand
• is used to return the right operand when the left operand is null.
• If the left operand is not null, return the left operand; otherwise, return the right operand.
• The right operand can be any value, including null.

Example:

<code class="csharp">object nullableObject = null;
object result = nullableObject ?? new object();  // result = new object()</code>

Summary

• ? Operators used For selecting values ​​under certain conditions, an exception is thrown if either operand is null. The
• ?? operator is used to return the right operand when the left operand is null and can handle null values ​​safely.

The above is the detailed content of What is the difference between operators ? and ?? in c#. For more information, please follow other related articles on the PHP Chinese website!