How to Catch Multiple Exceptions at Once in C#

By the end of this page, you will understand how to handle multiple expected exceptions in C# without duplicating code. You will learn when to use multiple catch blocks, exception filters, and safer alternatives such as TryParse-style methods that avoid exceptions entirely for expected invalid input.

In C#, each catch block handles one exception type at a time. If multiple exception types should trigger the same recovery logic, beginners often duplicate the same code in several catch blocks.

That works, but it can become noisy and harder to maintain.

The key idea is this:

• Catch only the exceptions you expect and can handle
• Let unexpected exceptions continue upward
• Prefer APIs that avoid exceptions for normal invalid input

In the Guid example, invalid input is not really an exceptional system failure. It is often just bad user input. In cases like that, a parsing method such as Guid.TryParse is usually better than using exceptions for control flow.

When you truly do need exception handling, C# gives you a few clean options:

• Separate catch blocks with shared logic moved elsewhere
• A single catch with an exception filter using when
• Refactoring the risky code into smaller operations

Why this matters in real programming:

• It reduces duplicated recovery code
• It makes error handling easier to read
• It avoids hiding real bugs behind broad exception handling
• It encourages use of safer APIs for expected failure cases

Think of exception handling like airport security.

• A known issue is something the staff is trained for, like a passenger carrying too much liquid.
• An unknown issue is something unusual that must be escalated.

You do not want security to treat every problem the same way. Instead:

• known problems get a standard response
• unknown problems get passed to someone higher up

In C#, that means you should catch only the exception types you expect. If two known problems should lead to the same action, you can route both to the same response instead of writing the same recovery code twice.

Basic approach: separate catch blocks

A straightforward way is to keep separate catch blocks:

try
{
    WebId = new Guid(queryString["web"]);
}
catch (FormatException)
{
    WebId = Guid.Empty;
}
catch (OverflowException)
{
    WebId = Guid.Empty;
}

This is valid C#, but the repeated assignment is not ideal.

Better approach for this case: Guid.TryParse

For parsing input, use TryParse when available:

if (!Guid.TryParse(queryString["web"], out var webId))
{
    WebId = Guid.Empty;
}
else
{
    WebId = webId;
}

This is cleaner because:

• no exceptions are thrown for invalid input
• the intent is obvious
• it is usually more efficient than throwing and catching exceptions

You can shorten it further:

WebId = Guid.TryParse(queryString["web"], out var webId)
    ? webId
    : Guid.Empty;

Consider this example:

string input = "not-a-guid";
Guid webId;

if (Guid.TryParse(input, out var parsedId))
{
    webId = parsedId;
}
else
{
    webId = Guid.Empty;
}

Step-by-step

1. input is assigned the value "not-a-guid".
2. Guid.TryParse(input, out var parsedId) tries to convert that string to a Guid.
3. The conversion fails because the text is not a valid GUID format.
4. TryParse returns false instead of throwing an exception.
5. The else block runs.
6. webId is set to Guid.Empty.

Now compare that with exception-based code:

string input = "not-a-guid";
Guid webId;

try
{
    webId = new Guid(input);
}
catch (Exception ex) when (ex is FormatException || ex  OverflowException)
{
    webId = Guid.Empty;
}

1. Parsing user input

A web app receives values from query strings, forms, or JSON payloads.

if (!int.TryParse(form["age"], out var age))
{
    age = 0;
}

2. Resetting state after expected validation failures

A service updates an object in several steps. If a known validation-related exception occurs, it resets the object to a safe state.

try
{
    ApplyUserChanges(profile);
}
catch (Exception ex) when (ex is FormatException || ex is InvalidOperationException)
{
    profile.Reset();
}

3. File and configuration handling

Applications often treat some failures as expected, such as invalid config values.

try
{
    settings.Port = int.Parse(config["Port"]);
}
catch (Exception ex) when (ex is FormatException || ex is OverflowException)
{
    settings.Port = 8080;
}

4. API input validation

Backend code commonly validates IDs, dates, and numeric values from requests. For normal invalid input, developers usually prefer validation or TryParse instead of exceptions.

In real C# codebases, developers usually follow these patterns:

Prefer TryParse for expected invalid input

If bad input is normal, avoid exceptions:

if (!DateTime.TryParse(request.DateText, out var date))
{
    return BadRequest("Invalid date.");
}

Use guard clauses early

Reject bad values before deeper logic runs:

if (string.IsNullOrWhiteSpace(queryString["web"]))
{
    WebId = Guid.Empty;
    return;
}

Use exception filters for shared handling

When multiple exception types need the same response, filters reduce duplication:

catch (Exception ex) when (ex is FormatException || ex is OverflowException)
{
    ResetObject();
}

Keep try blocks small

A small try block makes it clearer which code might fail and which exceptions are expected:

try
{
    WebId =  Guid(queryString[]);
}
 (Exception ex)  (ex  FormatException || ex  OverflowException)
{
    WebId = Guid.Empty;
}

Catching Exception without a good reason

Broken example:

try
{
    WebId = new Guid(queryString["web"]);
}
catch (Exception)
{
    WebId = Guid.Empty;
}

Why it is a problem:

• it may hide unrelated bugs
• it makes debugging harder
• it handles errors you did not intend to handle

Using exceptions for normal control flow

Broken example:

try
{
    age = int.Parse(input);
}
catch (FormatException)
{
    age = 0;
}

Better:

age = int.TryParse(input, out var parsedAge) ? parsedAge : 0;

Putting too much code inside one try

Broken example:

try
{
    LogRequest();
    WebId = new Guid(queryString["web"]);
    SaveToDatabase();
}
catch (Exception ex)  (ex  FormatException || ex  OverflowException)
{
    WebId = Guid.Empty;
}

new Guid(...) vs

Quick rules

• Catch only exceptions you expect and can handle.
• Do not catch Exception just to avoid writing more specific code.
• For parsing user input, prefer TryParse over exceptions.
• Keep try blocks small.
• Use exception filters with when if multiple exception types share the same handling.

Common patterns

Preferred for parsing

WebId = Guid.TryParse(queryString["web"], out var webId)
    ? webId
    : Guid.Empty;

Exception filter

try
{
    WebId = new Guid(queryString["web"]);
}
catch (Exception ex) when (ex is FormatException || ex is OverflowException)
{
    WebId = Guid.Empty;
}

Separate catch blocks

try
{
    DoWork();
}
catch (FormatException)
{
    ResetObject();
}
catch (InvalidOperationException)
{
    ResetObject();
}

Edge cases

Can C# catch multiple exceptions in one catch block?

Yes. A common modern approach is an exception filter:

catch (Exception ex) when (ex is FormatException || ex is OverflowException)

Is it bad to catch System.Exception in C#?

Usually yes for normal application logic, because it is too broad. It is sometimes acceptable at top-level boundaries such as application startup, logging, or global error handling.

What is better than catching parsing exceptions in C#?

Use TryParse methods when available, such as int.TryParse, DateTime.TryParse, or Guid.TryParse.

Should I use new Guid(string) or Guid.TryParse?

For user input or external input, prefer Guid.TryParse. It is clearer and avoids exception-based control flow.

Will exception filters hide unexpected exceptions?

No. If the filter condition does not match, the exception is not handled by that catch block and continues upward.

When should I keep separate catch blocks instead of using a filter?

• try, catch, and finally — the foundation of exception handling in C#.
• Exception filters — useful for handling multiple exception types with one recovery path.
• Guid.TryParse — the best fit for validating GUID input without exceptions.
• Guard clauses — help reject invalid input early before exceptions happen.
• Input validation — often a better solution than exception handling for expected bad data.
• throw and rethrowing exceptions — important when you need to preserve unexpected errors.
• FormatException — commonly seen when converting invalid text to a structured type.
• OverflowException — occurs when a numeric or conversion value exceeds valid bounds.