[Solved] what parameters are used in catch of try-catch block in c++? [closed]

by

Introduction

The try-catch block is a common feature of the C++ programming language. It is used to handle errors and exceptions that may occur during the execution of a program. The catch clause of the try-catch block is used to specify the parameters that will be used to handle the exception. In this article, we will discuss the parameters that are used in the catch clause of the try-catch block in C++. We will also discuss how these parameters are used to handle exceptions.

Solution

The catch block of a try-catch block in C++ typically takes a single parameter, which is an exception object. This exception object contains information about the type of exception that was thrown, as well as any additional data associated with the exception. The catch block can also take multiple parameters, which can be used to catch different types of exceptions.


try is a statement, so it can appear anywhere a statement can appear. It is designed to allow you to handle exceptions.

try
{
    //this code may throw!
}

After try block, there must be one or more handling blocks (or simply: handlers), that are defined as catch block:

catch(const std::exception& e)
{
}
catch(const MyException& e)
{
}
...

Formal parameter of catch block determines, what types of exceptions can be caught (and causes this block to be entered).

When an exception of type E is thrown by any statement in compound-statement (try block), it is matched against the types of the formal parameters T of each catch-clause (catch block) […], in the order in which the catch clauses are listed. The exception is a match if any of the following is true:

  • E and T are the same type (ignoring top-level cv-qualifiers on T)
  • T is an lvalue-reference to (possibly cv-qualified) E
  • T is an unambiguous public base class of E
  • T is a reference to an unambiguous public base class of E
  • T is a (possibly cv-qualified) pointer or a reference to a const pointer (since C++14), and E is also a pointer, which is implicitly convertible to T
  • T is a pointer or a pointer to member or a reference to a const pointer (since C++14), while E is std::nullptr_t.

Source: try-block.

solved what parameters are used in catch of try-catch block in c++? [closed]