1. What is a pointer?
Ans: Pointers are variables which stores the address of another variable. That variable may be a scalar (including another pointer), or an aggregate (array or structure). The pointed-to object may be part of a larger object, such as a field of a structure or an element in an array.

2. What are the uses of a pointer?
Ans: Pointer is used in the following cases
i) It is used to access array elements
ii) It is used for dynamic memory allocation.
iii) It is used in Call by reference
iv) It is used in data structures like trees, graph, linked list etc.

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3. Can we specify variable field width in a scanf() format string? If possible how?
Ans: All field widths are variable with scanf(). You can specify a maximum field width for a given
field by placing an integer value between the ‘%’ and the field type specifier. (e.g. %64s). Such a specifier will still accept a narrower field width.
The one exception is %#c (where # is an integer). This reads EXACTLY # characters, and it is the
only way to specify a fixed field width with scanf().

4. What is near pointer?
Ans: A near pointer is 16 bits long. It uses the current content of the CS (code segment) register (if
the pointer is pointing to code) or current contents of DS (data segment) register (if the pointer is pointing to data) for the segment part, the offset part is stored in a 16 bit near pointer. Using near pointer limits the data/code to 64kb segment.

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5. What is pointer to a pointer?
Ans: If a pointer variable points another pointer value. Such a situation is known as a pointer to a pointer.
Example:
int *p1,**p2,v=10;
P1=&v; p2=&p1;
Here p2 is a pointer to a pointer.

6. How are Structure passing and returning implemented by the complier?
Ans: When structures are passed as argument to functions, the entire structure is typically pushed on
the stack. To avoid this overhead many programmer often prefer to pass pointers to structure instead of actual structures. Structures are often returned from functions in a location pointed to by an extra, compiler-supported ‘hidden’ argument to the function.

7. What do the ‘c’ and ‘v’ in argc and argv stand for?
Ans: The c in argc(argument count) stands for the number of command line argument the program is
invoked with and v in argv(argument vector) is a pointer to an array of character string that contain the arguments.

8. What is the maximum combined length of command line arguments including the space between adjacent arguments?
Ans: It depends on the operating system.

9. How would you use the functions randomize() and random()?
Ans:
Randomize() initiates random number generation with a random value.
Random() generates random number between 0 and n-1;

10. How would you use the functions fseek(), freed(), fwrite() and ftell()?
Ans:
fseek(f,1,i) Move the pointer for file f a distance 1 byte from location i.
fread(s,i1,i2,f) Enter i2 dataitems,each of size i1 bytes,from file f to string s.
fwrite(s,i1,i2,f) send i2 data items,each of size i1 bytes from string s to file f.
ftell(f) Return the current pointer position within file f.
The data type returned for functions fread,fseek and fwrite is int and ftell is long int.

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