What is stack overflow with example?

A Stack overflow is when a process will only ever be able to add or remove the value of a stack, and each time it tries to add to that stack, it will use up all available space on the stack.

The stack grows downwards (smallest values at the top) but when you add to the stack (let's say push 3 onto the stack), the space in which you have put the 3 will be added above it, leaving only room for the 3 above it, and no room at all below it. When your process continues to do this, it will continue using up the available space in the stack. Eventually it will reach a point where it won't be able to add anymore and it will no longer be able to push the contents onto the stack.

For more details on the subject read this question: How does memory management of stack work? There is also a good article on it here: The stack can grow as needed. Each level of the stack holds its own size of space, so it starts with an empty space and goes forward in a line.

Each function has its own space allocated for local variables. These spaces are usually linked to the stack and it grows in size with the number of variables. Functions can store their own return addresses into the stack or into the heap. The C language spec allows for the stack to grow up to 4k bytes. Most compilers will enforce that if you exceed this size. The operating system may limit it if the system is running low on memory. And so on.

You might want to check out this answer. There is a decent explanation on how stacks work.

What is a stack overflow error?

The stack is a list of storage locations where local variables are allocated while the program is running.

If a variable is used more than once it can occupy space in multiple locations of the stack. The stack therefore becomes full and cannot keep any more variables. If it gets full, the error occurs.

This happens when the stack gets too full and can't hold any more variables. Stack overflows can occur either at the time of calling the function or within the function.

What causes a stack overflow? There are many causes for a stack overflow error, here we will describe the few causes which are responsible for this error. Improper design of the program. When the programmer has designed the code in an improper way. The design means how and what are the variables are used. If the variables are used incorrectly the stack overflows occurs. For instance, in following program the variables x and y are never null, so they will never be used beyond the declaration and they should be removed from the main() method.

#includeusingnamespacestd;intmain(). Program not checking the memory limits. The program may pass memory checker but it doesn't mean that the program is optimized enough to pass the limits because if it exceeds the limits stack overflows occurs. To avoid this check memory usage inside the program before compilation.

Memory usage outside the stack. If the data structure takes more memory in such a way that the data occupies more space and this data is beyond the capacity of the stack, then it will cause the stack to overflow. Function recursion The number of functions is limited by the stack and every recursive call is put on the stack and consumes more space which leads to overflowing the stack. Infinite loop inside the function. There is an infinite loop condition in which the compiler doesn't allow even if the maximum recursion depth is reached. This also causes the stack overflow.

What is an example of an overflow error?

An overflow error can occur when a computation is forced to be large enough so that memory or logic components (RAM, counters, etc.) cannot be used to contain the result of the computation. For example, one counter might overflow into a second counter because both could not hold the larger count value.

Another example might be a computer that has 16-bit registers and a data bus between the registers and the memory, but this example also suffers from overflows because of the fact that all 32 bits of the register are not independently accessible. In general, overflows may occur when the computed data, which is represented as a number or a vector in some sort of machine model, is too large to be accommodated by a component of a computer. Overflow errors may be classified according to the level of the machine model. The most basic type of overflow errors occur when the number or vector exceeds the capacity of a memory location or array element. However, there may also be overflow errors, called bounding overflow errors, when the number is too small for certain components. A third type, arithmetic overflow errors, occurs when a result is obtained from mathematical operations that do not have a maximum value in the computer's arithmetic. Such errors may result in the generation of incorrect results.

In other words, overflow errors are not defined in terms of specific computer registers or circuits. Instead, these overrunning components serve to define an upper limit to the correct answers, for example, a "memory cell" or "register" overflowing into an adjacent memory cell or register would produce either an infinite loop if data is repeatedly passed across multiple cells, or the value would not be updated to reflect the new information if the register holds sequential integers.

What is the difference between bounds errors and arithmetic errors? The difference is that it is always possible to recover from a bounds error because if the correct value does not fit in a fixed-size block, then the program will usually attempt to move the correct value into a different block. Unfortunately, if a bounds error is discovered within a data-structure, it is almost impossible to correct, so in this case you might consider the program to be buggy.

On the other hand, an arithmetic overflow may be correct, but it may not have sufficient context to tell you the correct answer.