Do i have to check for null after p = new fred()?, C/C++ Programming

Assignment Help:

A: No. (Excluding if you have an old compiler, you might have to force the new operator to throw an exception if it runs out of memory.)

This turns out to be a real pain to always write down explicit NULL tests after each new allocation. Code like the following is extremely tedious:

Fred* p = new Fred();

if (p == NULL)

throw std::bad_alloc();

If your compiler doesn't support (or if you reject to use) exceptions, your code may be even more tedious:

Fred* p = new Fred();

if (p == NULL) {

std::cerr << "Couldn't allocate memory for Fred" << std::endl;

abort();

}

In C++, if the runtime system can't allocate sizeof(Fred) bytes of memory throughout p

= new Fred(), a std::bad_alloc exception will thrown. Unlike malloc(), new never returns

NULL!

Then you should simply write:

Fred* p = new Fred(); // No require to check if p is NULL

Though, if your compiler is old, it might not yet support this. Determine by checking your compiler's documentation under "new". If you hold an old compiler, you might have to force the compiler to have this behavior.

 

Note: If you are using Microsoft Visual C++, to obtain new to throw an exception while it fails you have to #include some standard header in at least one of your .cpp files. For instance, you could

#include (or or or ...).

 

 


Related Discussions:- Do i have to check for null after p = new fred()?

Is there anything you can do in c++ which you cannot do in c, A: No. There ...

A: No. There is nothing you can do in C++ which you cannot do in C. In spite of everything

Lcm, lcm program.

lcm program.

Define statements to define the constants, the problem description. The ...

the problem description. The order of the C Program should be as follows: Variables and constants Use #define statements to define the constants. Use arr

Decodethecode.h, decodes the sending smuggler string from the number format...

decodes the sending smuggler string from the number format into plain text

Lowest cost entry, code for solving optimal solution for matrix

code for solving optimal solution for matrix

Define the int data type of c language, Define the Int Data Type of C Langu...

Define the Int Data Type of C Language? The int is used to define integer numbers. The Integers are whole numbers with a range of values supported by a particular machine and t

Explain the class invariant, Explain the class invariant. - It's a cond...

Explain the class invariant. - It's a condition that ensures correct working of a class and defines all the valid states for an object. - When an object is created class inv

Data type, what is virtual datatype

what is virtual datatype

Which one would you prefer - a macro or a function, Which one would you pre...

Which one would you prefer - a macro or a function? Actually it depends on the purpose of program! - In case of macros, corresponding code is inserted directly into your sou

Functions, write a program to calculate gross salary and net salary using h...

write a program to calculate gross salary and net salary using hra da pf in c++

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd