The difference between new and malloc

new and malloc The difference between

1、new Allocate memory from free storage ,malloc Allocate memory from the heap . Free storage is C++ be based on new An abstract concept of an operator , Usually through new Operator for memory request , This memory is the free storage area . And heap is an operating system term , It is a special memory maintained by the operating system , For dynamic allocation of program memory . So can a free storage area be a heap （ The problem is equivalent to new Whether memory can be allocated dynamically on the heap ）, It depends. operator new Implementation details . Free storage can be more than just a heap , It can also be static storage , It's all up to you operator new Where to allocate memory for objects .
2、new、delete Returns a pointer to a data type ;malloc、free The return is void The pointer .
3、 Use new Operators do not need to specify the size of memory block when applying for memory allocation , The compiler computes itself based on the type information ; Use malloc You need to explicitly indicate the size of memory required .
4、new You can call the constructor of an object , Corresponding delete Call the corresponding destructor ;malloc Just allocate memory ,free Just reclaim memory , Construction and destructors are not executed . stay new When an object , The first call malloc Allocate memory space for objects , And then call the constructor of the object. .delete Will call the object's destructor , And then call free Reclaiming memory .
5、new、delete It's the operator , Can overload ;malloc、free Is the function , Can be rewritten ( Cover ).