Decision Making- If statement in C++ (OOPs)

It is used whenever any condition is to be implemented by the user it means some conditions like:
1. If the price of the item is more than 5000 then discount is 10%.
2. If the students marks are greater than 60% then he should be in 1st division.

Simple C++ (OOPs) Programs

/* Program to enter two values and perform addition and multiplication operation*/

#include<iostream.h>
#include<conio.h>
main()
{
      int n1,n2,sum,mul;
      cout<<"\n Enter any two numbers";
      cin>>n1>>n2;
      sum=n1+n2;
      mul=n1*n2;
      cout<<"\n Sum of two numbers is "<<sum;
      cout<<"\n Multiplication of two numbers is "<<mul;
      getch();
}

Structure of C++ (OOPs) Program

C++ Programming Language (OOPs)

Files Input/Output in C-language

A file is a place on the disk where the group of related data are stored. The first function is to be performed when we are accessing the files is to open a file. Opening a file establishes a link between the program and the operating system about which file we want to access for what purpose. We provide the operating system to which file we want to access and for what purpose. For accessing a file we just have to name the file and plan whether we want o read data from the file or write data onto the file. The syntax for opening is:

FILE *fp;
inbuilt structure
fp= fopen( “file name”, “mode”);

Union in C-language

Union is that data structure which is also user defined data type but to define a union keyword union  is used instead of struct.

Structure in C-language

Structure is the user defined data type which can store heterogeneous data i.e. data of different types. It means in structure member with all possible data type can be used and there is no restriction that elements of the structure are stored at adjacent memory locations. Structure is declared with key word struct followed by its name and then by block. 

Pointers in C-language

Pointer is that variable which stores the memory address of another variable. It means pointer is itself a variable which stores hex-decimal address of the location.

Library String Function

Call by Value and Reference

Recursive Function

This function is that function which calls itself again and again until some base criteria is fulfilled. It means it is that prototype function in which its name appears as a statement at least once. 

Prototype Function

When a function is defined after the main function it needs to be declared in the declaration section of the program. This declaration section statement is known as function prototype.
This tells the calling function the type of value that will be returned with the name of the function and list of argument data types.

Syntax:
return type  function name(Argument list);
int fun (f1,f2);

Function with parameter with return

This function can also return a value from the called function to the calling function i.e. the output which is printed in the main function whenever the value will be returned to the main function it can be printed thereafter. Now the function type should not be void because function will return a value. Therefore, it’s overall type is decided by the type of value it returned (int, float etc.).

Function with parameters with no return

Function can also use parameters and these parameters should be specified as a list along with function name with specific data types and each argument should be separated by ‘,’.
In function with parameter or arguments two types of arguments are used ACTUAL PARAMETERS and FORMAL OR DUMMY PARAMETERS.

Function without parameters in C-language

Such functions are defined same with return type followed by used defined name and a pair of parenthesis () and a block of codes. These functions uses two type of variables AUTOMATIC STORAGE CLASS VARIABLES and GLOBAL VARIABLES.

Function in C-language

A function is block of codes that performs a particular task, this block is given a name and whenever we want to execute this block we simply write the name of the function. Function is a small sub-program which is a self contained block of statements and the function which is defined by the user is User Defined Functions.

Arrays in C-language

Array is an arrangement of same type of data at adjacent memory locations. Array is useful whenever large volume of data is to be processed and stored in the memory.

Suppose an average marks are to be calculated from all the students in the school. This is difficult to find the sum of marks of all students. In this situation an array is the best alternative. Its divided in two categories:

1. Single / 1-D Array
2. Multi-dimension Array

Switch Statement

This statement is also used for decision making. Here key word is switch followed by control variable and followed by it’s block.
In the block of switch statement multiple cases are used and each ends with break statement this is also called as early exit loop.
Out of all the cases only that case will run whose value matches with the control variable.

Loop Control- Nested for loop

/*Program to print star matrix of order (4*5) */

#include<stdio.h>
#include<conio.h>
void main()
{
     int i,j;
     for(i=0;i<4;i++)
     {
                     for(j=0;j<5;j++)
                     {
                                     printf("*");
                                     }
                     printf("\n");
                     }
     getch();
     }

Loop Control- for loop

“for” loop is also structure control loop as program will run or execute if the initial condition is true otherwise it will terminate and program will run until some condition is fulfilled.

FORMAT:
for(expression1;expression2;expression3)
{
Statement1;
Statement2;
}