0
There is no operator new in C.
In C++11, there are three versions of operator new, all of which can be overridden. Default behaviour is as follows:
(1) throwing allocation
void* operator new (std::size_t size);
If an allocation of the given size cannot be met, an exception will be thrown. There is no return value after an exception is thrown.
(2) nothrow allocation
void* operator new (std::size_t size, const std::nothrow_t& nothrow_value) noexcept;
If an allocation of the given size cannot be met, nullptr is returned.
(3) placement
void* operator new (std::size_t size, void* ptr) noexcept;
Always returns ptr. You use this version when memory has already been allocated and you are merely providing placement for an object within that allocation.
What else can I help you with?
Which is the unary operator used to dereference a pointer and return the value stored in it?
The asterisk (*) operator dereferences a pointer and returns the value stored in the memory pointed to by the pointer.
Is it possible to compare the return value of a function call with another value using a relational operator?
pancakes
How do you use a assignment statement?
Assignment is not a statement, it is an operator. You use the assignment operator in assignment expressions. int x = 100; // assigns the value 100 to the memory location referred to by x. int y = x; // assigns the value of x (100) to the memory location referred to by y. Classes can override and overload the assignment operator to ensure correct assignment behaviour, particularly important when the class includes a member pointer to memory owned by an instance of the class, or to ensure correct typecasting between objects of different types. class MyClass{ public: MyClass():m_pNum=new int(){} // default ctor MyClass(const MyClass):m_pNum=new int(*MyClass.m_pNum){} // copy ctor ~MyClass(){ delete( m_pNum ); } // dtor public: MyClass & operator= (int); // typecast assignment MyClass & operator= (MyClass &); // standard assignment private: int * m_pNum; // memory allocated by constructors. }; // Assignment operator override required to typecast an integer. MyClass & MyClass::operator= (int num){ *m_pNum = num; return( *this ); } // Assignment operator override required to ensure two instances // of MyClass do not share the same memory. MyClass & MyClass::operator= (MyClass & myClass){ *m_pNum = *myClass.m_pNum; return( *this ); }
What is a use of dereferencing operator?
A pointer variable contains the address to some memory location. "Dereferencing" the pointer means getting the value stored at that memory location.
Associativity has no role to play unless the precedence of operator isHow much memory is required to store a value of type double?
yes
Which is the unary operator used to dereference a pointer and return the value stored in it?
The asterisk (*) operator dereferences a pointer and returns the value stored in the memory pointed to by the pointer.
Is it possible to compare the return value of a function call with another value using a relational operator?
pancakes
How do you use a assignment statement?
Assignment is not a statement, it is an operator. You use the assignment operator in assignment expressions. int x = 100; // assigns the value 100 to the memory location referred to by x. int y = x; // assigns the value of x (100) to the memory location referred to by y. Classes can override and overload the assignment operator to ensure correct assignment behaviour, particularly important when the class includes a member pointer to memory owned by an instance of the class, or to ensure correct typecasting between objects of different types. class MyClass{ public: MyClass():m_pNum=new int(){} // default ctor MyClass(const MyClass):m_pNum=new int(*MyClass.m_pNum){} // copy ctor ~MyClass(){ delete( m_pNum ); } // dtor public: MyClass & operator= (int); // typecast assignment MyClass & operator= (MyClass &); // standard assignment private: int * m_pNum; // memory allocated by constructors. }; // Assignment operator override required to typecast an integer. MyClass & MyClass::operator= (int num){ *m_pNum = num; return( *this ); } // Assignment operator override required to ensure two instances // of MyClass do not share the same memory. MyClass & MyClass::operator= (MyClass & myClass){ *m_pNum = *myClass.m_pNum; return( *this ); }
What is a use of dereferencing operator?
A pointer variable contains the address to some memory location. "Dereferencing" the pointer means getting the value stored at that memory location.
How you use malloc function in c?
void* malloc (size_t bytes); This means that malloc takes an argument which is the size of memory to allocate and returns a pointer to that memory which has been allocated. If the return value is NULL, then the request could not be satisfied. Each call to malloc must be balanced with a corresponding call to free, to release the memory. int pa = NULL; pa = (int*) malloc (sizeof(int) * 1000); /* allocate 1000 ints */ if (pa == NULL) throw exception... ... use pa free (pa); pa = NULL;
Associativity has no role to play unless the precedence of operator isHow much memory is required to store a value of type double?
yes
Delete memory release operator in c plus plus?
You can't physically delete memory, you can only delete a pointer to allocated memory, which subsequently releases the memory back to the system. The operator is delete, passing the pointer as the operand. If the pointer points to an array, then you must also use the index operator [] in front of the pointer name.int main(){// pointer to an int type with value 100int* ptr_int = new int(100);// ... use pointer ...// release the integerdelete ptr_int;// pointer to an array 100 int types (with undefined values)int* ptr_int_array = new int[100];// ... use array ...// release the arraydelete [] ptr_int_array;return(0);}
What are subscripts in c language?
Subscripts are used when accessing arrays. An array is a contiguous block of memory containing two or more elements of the same type. Since each element is the same length, it is trivial to work out the offset address of one element relative to another using a zero-based index. For any type T, the type T[n] is an array of Ts with indices in the range 0 to n-1. We can also create arrays at runtime by allocating sufficient memory on the heap for the given type: void f(int n) { if (n<1) return; // cannot allocate 0 elements! int* ptr = malloc (n * sizeof(int)); // allocate memory for n integers if (ptr!=0) return; // ensure memory was allocated! ptr[0] = 42; // use subscript operator to assign a value to the first element // assign to other elements... // use array... free (ptr); // release memory as soon as we're finished with it }
Which data type assigns values automatically?
None of the data types available in C assigns valur to the variable. Initially all the variables have a garbage value. But when we use calloc() to allocate memory dynamically only then it assigns NULL to the memory block assigned.
Which value is modified by an operator?
The value of the variable which is on the left side of the assignment operator. Example: a = 2
What is the value of relocation register?
what is resource allocate register why it is used
Which operand should be passed in the binary overloaded operator function as a second operand?
The right-hand operand; the r-value of the operator. Unary operators have one operand while tertiary operators have three operands. All binary operators have two operands, the l-value and the r-value. The l-value is the operand to the left of the operator while the r-value is the operand to the right of the operator. Thus, in the expression x + y, x is the l-value while y is the r-value. When overloading binary operators in a class, you need only specify the r-value. The l-value is the instance of the class to which the operator applies and therefore does not need to be specified. For instance: class MyClass { public: MyClass(int data=0):m_data(data){} // default constructor int operator+ (const int rhs) const {return(m_data+rhs);} private: int m_data; }; While this allows you to return the sum of your class instance and an integer, it does not allow you to return the sum of an integer and an instance of your class. For example: MyClass obj(5); int x = 10; int y = obj + x; // OK! y is 15. int z = x + obj; // Compiler error! No operator exists that accepts an r-value of type MyClass. To fix this error and allow for two-way addition, you must declare a binary operator overload outside of the class. You cannot do it inside the class because the l-value is an int, not an instance of MyClass. The external overload requires two parameters, the l-value and the r-value of the operator: int operator+(const int lhs,const MyClass& rhs) {return(rhs+lhs);} Note that the implementation simply reverses the operands. This is functionally equivalent to making the following explicit call: return(rhs.operator+(lhs)); Note also that since MyClass::operator+ is a public operator of MyClass, this overload does not need to be declared a friend of MyClass (a common misconception). However, the overload must be declared in the same file where the class is declared since it is only of relevance to MyClass but should be made available wherever MyClass is accessible.
