# std::bad_array_new_length

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< cpp‎ | memory‎ | new

Defined in header `<new>` |  |
class bad_array_new_length; |  | (since C++11)

`std::bad_array_new_length` is the type of the object thrown as exceptions by the new-expressions to report invalid array lengths if

1. Array length is negative,
2. Total size of the new array would exceed implementation-defined maximum value,
3. The number of initializer-clauses exceeds the number of elements to initialize.

Only the first array dimension may generate this exception; dimensions other than the first are constant expressions and are checked at compile time.

Inheritance diagram

### Member functions

(constructor) | constructs a new `bad_array_new_length` object (public member function)
operator= | replaces the `bad_array_new_length` object (public member function)
what | returns the explanatory string (public member function)

## std::bad_array_new_length::bad_array_new_length

bad_array_new_length() noexcept; | (1) | (since C++11)
bad_array_new_length( const bad_array_new_length& other ) noexcept; | (2) | (since C++11)

Constructs a new `bad_array_new_length` object with an implementation-defined null-terminated byte string which is accessible through `what()`.

1) Default constructor.
2) Copy constructor. If `*this` and `other` both have dynamic type `std::bad_array_new_length` then std::strcmp(what(), other.what()) == 0.

### Parameters

other | - | another exception object to copy

## std::bad_array_new_length::operator=

bad_array_new_length& operator=( const bad_array_new_length& other ) noexcept; |  | (since C++11)

Assigns the contents with those of other. If *this and other both have dynamic type `std::bad_array_new_length` then std::strcmp(what(), other.what()) == 0 after assignment.

### Parameters

other | - | another exception object to assign with

### Return value

*this

## std::bad_array_new_length::what

virtual const char* what() const noexcept; |  | (since C++11)

Returns the explanatory string.

### Parameters

(none)

### Return value

Pointer to a null-terminated string with explanatory information. The string is suitable for conversion and display as a std::wstring. The pointer is guaranteed to be valid at least until the exception object from which it is obtained is destroyed, or until a non-const member function (e.g. copy assignment operator) on the exception object is called.

### Notes

Implementations are allowed but not required to override `what()`.

## Inherited from std::bad_alloc

## Inherited from std::exception

### Member functions

(destructor) [virtual] | destroys the exception object (virtual public member function of `std::exception`)
what [virtual] | returns an explanatory string (virtual public member function of `std::exception`)

### Example

Three conditions where `std::bad_array_new_length` should be thrown:

Run this code

    #include <climits>
    #include <iostream>
    #include <new>

    int main()
    {
        try
        {
            int negative = -1;
            new int[negative];
        }
        catch (const std::bad_array_new_length &e)
        {
            std::cout << "1) " << e.what() << ": negative size\n";
        }

        try
        {
            int small = 1;
            new int[small]{1,2,3};
        }
        catch (const std::bad_array_new_length &e)
        {
            std::cout << "2) " << e.what() << ": too many initializers\n";
        }

        try
        {
            long large = LONG_MAX;
            new int[large][1000];
        }
        catch (const std::bad_array_new_length &e)
        {
            std::cout << "3) " << e.what() << ": too large\n";
        }

        std::cout << "End\n";
    }

Possible output:

    1) std::bad_array_new_length: negative size
    2) std::bad_array_new_length: too many initializers
    3) std::bad_array_new_length: too large
    End

### See also

operator new operator new[] | allocation functions (function)
bad_alloc | exception thrown when memory allocation fails (class)

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