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

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;



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


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 ...).



Posted Date: 3/19/2013 8:39:01 AM | Location : United States

Related Discussions:- Do i have to check for null after p = new fred()?, Assignment Help, Ask Question on Do i have to check for null after p = new fred()?, Get Answer, Expert's Help, Do i have to check for null after p = new fred()? Discussions

Write discussion on Do i have to check for null after p = new fred()?
Your posts are moderated
Related Questions
Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve between two points can b

Important Note: No course works, which have been submitted via hard copies or emails, will be accepted a short essay below edited in a document (word, other) files with

Question : (a) Define the following Object-Oriented terms: (i) Encapsulation (ii) Inheritance (iii) Abstraction (iv) Polymorphism. (b) What are objects in Lingo progra

Problem : Luminous Jewels - Polishing Necklace Byteland county is very famous for luminous jewels. Luminous jewels are used in making beautiful necklaces. A necklace consists of v

Create a C language code, only one program, to implement the following task. Task: Write C code for a program that implements a digital clock (HH:MM:SS). The clock inclu

Presently we are using several spreadsheets to give weekly activity and income reports. Much of the information is being frequently re-keyed into several spreadsheets - we are look

Consider text comprised of sentences and sentences comprised of words. Words in a sentence will be space delimited. Given a text and K strings, task is to find out the number valid

1. Jewels can only be removed for polishing from either end of the necklace (i.e. head or tail) 2. Once a jewel type is removed from the necklace, all other instances of the same j

overload assignment opertor to assign the data of one object to anthor