Memory

Question 1

What is a decimal system?

Answer 1

a base-10 to represent numbers ( 0,1,2,3,4,5,6,7,8,9) and combining those to create larger numbers.

Question 2

What is the Binary system?

Answer 2

A base-2 to represent values. Only values used in this system are 0 and 1

Question 3

What is the Hexadecimal System

Answer 3

The hexadecimal system, aka base-16, is a much more concise way to express the data on a computer’s system. (0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f)

Question 4

Why is hexadecimal more concise to express computer data?

Answer 4

Hexadecimal makes this mapping easy because a group of 4 binary digits (bits) is able has 16 different combinations, and each of those combinations maps to a single hexadecimal digit.

Question 5

1 byte = ?? bits

Answer 5

1 byte = 8 byte

Question 6

What is a nibble

Answer 6

a Nibble = 4 bits and equals one hexadecimal unit

Question 7

How many bits is an integer

Answer 7

an integer is 32 bits (= 4 bytes)
The max value = 2.147.483.647 because this is the maximum number reachable with 32 bits

Question 8

How many bits is a Long

Answer 8

a Long is 64 bits (= 8 bytes)
Max value = 9,223,372,036,854,775,807

Question 9

How many bits is float

Answer 9

an float is 32 bits (= 4 bytes)

Question 10

How many bits is a char

Answer 10

a char is 16 bits (=2 bytes)
It ranges from 0 to 65.535
can be used with uni-code

Question 11

What is overflow?

Answer 11

Trying to store a larger number than is possible in a datatype.
For example 3.000.000.000 in an integer

Question 12

What is a pointer in C

Answer 12

Adress to a memory location where an object is stored

Question 13

How to check with C what the value in a memory adress is

Answer 13

& — If x is an int-type variable, then &x is a pointer-to-int whose value is the address of x.

Question 14

What does ‘*’ do for a pointer in C

Answer 14

Go To memory adress - It “goes to the reference” and accesses the data at that memory location, allowing you to manipulate it at will.

This is just like visiting your neighbor. Having their address isn’t enough. You need to go tothe address and only then can you interact with them.

Question 15

What is a call stack?

Answer 15

When you call a function, the system sets aside space in memory for that function to do its necessary work. Those chunck of memory we call stack frames or function frames.

Those function are stored in a call stack

Question 16

What happens to the call stack when you use a function?

Answer 16

*These frames are arranged in a stack. The frame for the most recently called function is always on the top of the stack.

*When a new function is called, a new frame is pushed on to the top of the stack and becomes the active frame.

*When a function finishes its work, its frame is popped off of the stack, and the frame immediately below it becomes the new, active, function on the top of the stack. This function picks up immediately where it left off.

Question 17

What is stack overflow?

Answer 17

What is stack overflow? A stack overflow is a type of buffer overflow error that occurs when a computer program tries to use more memory space in the call stack than has been allocated to that stack.

Question 18

What is Heap memory?

Answer 18

Heaps are memory areas allocated to each program. Memory allocated to heaps can be dynamically allocated, unlike memory allocated to stacks.

Question 19

What is a Memory Leak?

Answer 19

A memory leak is a type of resource leak that occurs when a computer program incorrectly manages memory allocations in a way that memory which is no longer needed is not released

Question 20

Where is the Heap en Stack memory in your PC

Answer 20

in the RAM memory
Random Access Memory