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C++ stdexcept runtime_error Class

❮ stdexcept Classes


Example

Throw a runtime_error when a file is not found:

bool fileFound = false;

try {
  if (!fileFound) {
    throw runtime_error("Could not find the file");
  }
  cout << "Reading the file";
} catch (const runtime_error& e) {
  cout << e.what();
}

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Definition and Usage

A runtime_error reports a problem that happens while the program runs. These problems often come from outside the program, like a file that is missing, or a network connection that is lost. The program cannot know about them before it runs.

It is the parent class of overflow_error, range_error and underflow_error. Use runtime_error when none of them fits.

The runtime_error class is defined in the <stdexcept> header file.

Tip: catch (const runtime_error& e) also catches all the classes that come from runtime_error, like overflow_error.


Syntax

throw runtime_error(message);

Catch it with catch (const runtime_error& e), and use e.what() to get the message.

Parameter Values

Parameter Description
message Required. A text that describes the error, as a string or as text in double quotes. what() returns this text.

Technical Details

Returns: A runtime_error object. Its what() function returns the message.

Related Pages

Read more about exceptions in our Exceptions Tutorial.


❮ stdexcept Classes

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