0
The same chip of RAM may be used as stack memory when running one program and later used as heap memory when running some other program.
The difference is in how they are used.
Stack
Often a function or method calls another function which in turn calls another function etc.
The execution of all those functions remains suspended until the very last function returns its value.
All the information required to resume the execution of these functions is stored on the stack.
In particular, local variables are stored on the stack.
Local variables are often stored for short amounts of time while a function/method block uses them to compute a task.
Once a function/method has completed its cycle, the space on the stack used by all local variables is freed.
This chain of suspended function calls is the stack, because elements in the stack (function calls) depend on each other.
The stack is important to consider in exception handling and thread executions.
Heap
Heap
The heap is simply the memory used by programs to store global variables.
Element of the heap (variables) have no dependencies with each other and can always be accessed randomly at any time.
All global variables are stored in heap memory.
All variables dynamically created by the program with "new()" or "malloc()" or similar commands are also stored on the heap.
In some programming languages, all instances of an object, including all the attributes of that instance, are stored on the heap.
In those programming languages, local variables of a function that have object type are implemented as creating the new object on the heap,
and storing a reference to that object in the local variable, which is on the stack.
When that function exits, the heap memory used by each local variable that has object is freed, and then all the stack used by that stack is freed.
Comparison
A Heap reference is also stored in Stack memory until the life cycle of the object has completed. Inside the Heap reference all the the contents of the object are stored whereas with a local variable only the variable contents are stored in the stack.
Example:
Stack
var blue
var red
ref 0x456783 (Heap reference)
var tom
ref 0x498702 (Heap reference)
var diane
Heap (0x456783)
name => Susan
age => 26
city => London
height => 5'7
sex => female
Heap (0x498702)
name => Paul
age => 21
city => Glasgow
height => 6'0
sex => male
In addition to heap memory and stack memory, a completely separate section of memory stores the constructors and other methods of a class/object.
Wiki User
∙ 2012-04-30 03:26:54
Add your answer:
Earn +20 pts
Difference between Heap memory and Stack memory?
Stack memory is static memory within the program's data segment and is allocated at compile time. Heap memory is dynamic memory allocated upon the free store at runtime.
What is the difference between stack and heap memory in C?
The stack is a local memory reserve where the program stores variable and function data. The heap is a special memory reserve where the programmer can dynamically allocate memory from. The heap is useful when the programmer doesn't know how large to make certain variables, he just constructs one of the right size during run-time.
What is the difference between the stack and the heap?
The stack is a local memory reserve where the program stores variable and function data. The heap is a special memory reserve where the programmer can dynamically allocate memory from. The heap is useful when the programmer doesn't know how large to make certain variables, he just constructs one of the right size during run-time.
What is the difference between allocating memory through heap and malloc?
Nothing, malloc does allocate memory from the heap.
What is in between stack and heap?
Bundle, Perhaps.
Where the Memory is allocated for a variable in a program?
if a variable is of value type memory is allocated on stack memory.. if it is of reference type,memory is allocated on heap memory..
Where are pointer variables stored in C memory?
Pointers can be stored in static memory, on the stack or on the heap, the choice is yours.
What is difference between heap and stack memory in java?
Stack memory is used for variables, and allocated and deallocated in a LIFO (last-in first-out) fashion. That is, if a variable is allocated, it is just assigned a space on the stack, and the stack pointer is increased; if the method that uses the variable is finished (there is an implicit or explicit "return"), the stack pointer is adjusted downward again. Heap is an area of memory used to assign objects. This is a bit more chaotic; first, objects can have just about any size - small, or large. Second, objects may continue existing after the method that created them ends its execution. On the heap, the Java Virtual Machine just assigns objects in whatever available space it finds. Every now and then, the Garbage Collector does a cleanup, releasing objects from the heap that are no longer used.
Can heap implement recursion?
Heap is a data-structure, it cannot implement anything. On the other hand, it is true that: 1. Recursive routines might use heap. 2. You can use dynamic memory allocation (heap), to implement a stack; and use the stack to implement recursion.
Where do objects and references stored in memory in java?
Objects are stored in an area of memory called the "heap", whilst reference variables are stored in the "stack". These are both parts of the computer's RAM memory; the Java Virtual Machine (JVM) simply reserves part of the memory available to it for the stack and for the heap, and manages them accordingly.
Why it is required to create mainframe object on the heap?
You need to create the mainframe object on the heap so that the object does not go out of scope and get automatically deleted when your function exits. You could create it on the stack if the function doing that does not exit until everything is deleted, such as in the main loop of CWinApp. There are also issues with available memory in stack versus heap, as the stack size is preallocated while the heap can grow to the size of available memory.
Static and dynamic memory allocation in c plus plus?
int stc; // static int* dyn = new int; // dynamic The difference between the two is that the former is allocated on the stack, in the program's data segement, while the latter is allocated on the heap, in free memory. The stack is very much smaller than the heap, thus the stack should only be used for small and simple variables that are used often but that do not change size (such as small static arrays), while the heap should be used for much larger structures, structures that vary in size (such as dynamic arrays), or temporary structures that are seldom required or highly volatile. Note that both stc and dyn in the example above are allocated on the stack, but the memory pointed to by dyn is allocated on the heap. dyn simply stores the memory address of that allocation.
