CS201 Final Term Notes by Almas Afzal

CS-201 FINAL TERM NOTES (THEORETICALLY) · 1.Pre-processor: · Old: #include <iostream.h> · New: #include <iostream> · 2.Include Directive: · It is written as: · #include “myHeaderfile.h” · 3. Define Directive:

Also called Macros. Macros is a special name, which is substituted in the code by its definition and, as a result we get an expand code.

With the define directive , we can define PI as:

#define Pi 3.1415926

Jab macros ko use Kiya jata hai to is mein assignment operator Nahin lagaya jata,, without Assignment operator, value assign ki jati hai

4. Pre-processor directives (Mcqs) · • #include <filename> · • #include “filename” · • #define · • #undef · • #ifdef · • #ifndef

• #if

• #else · • #elif · • #endif · • #error · • #line · • #pragma · • #assert · 5. Macros:

Macros are classified into two categories. First: The first type of macros can be written using #define. The value of PI can be defined as:

#define Pi 3.1415926

Second: The second type of macros takes arguments. It is also called a “parameterized macros”.

Consider the following: · #define square (x) x*x · Correct definition of the macros will be: · #define square (x) ((x)*(x)) · 1.Memory Allocation:

Memory will be allocated during the execution of program.

There are two types of memory · 1. Static · 2. Dynamic

Static: Static Allocation is also called “Compile time allocation”. This memory allocation is defined at the time when we write the program while exacting knowing how much memory is required. Static memory stored in “Stack”. Dynamic: Whenever we don’t know in advance how much memory space would be required , it is better to use dynamic memory allocation. Dynamic memory stored in “heap”.

2.Void Pointer:

Jab b ap void pointer ko use Karen gy to sab say pehly apko uski “casting” krni pryge....

Casting: Cast means the conversion of “void” into a type of pointer that can be used for native data type like int, char, float etc.....