//Write a program to demonstrate the use of printf and scanf statements to read and print values of variable of different data types.

#include<stdio.h>
//#include<conio.h>   (Since the conio.h header file was inbuild in one compiler)
#include<math.h>
int main()
{
int num;
float amt;
char code;
double pi;
long int population_of_india;
char msg[10];

//all the input of this one compiler were in STDIN Section

printf("\n Enter the value of num : ");
scanf("%d",&num);
printf("\n Enter the value of amt : ");
scanf("%f",&amt);
printf("\n Enter the value of pi : ");
scanf(" %lf",&pi);
printf("\n Enter the value of population of India : ");
scanf("%ld",&population_of_india);
printf("\n Enter the value of code : ");
scanf(" %c",&code);
printf("\n Enter the value of message : ");
scanf("%s",&msg);
printf("\n NUM =%d \n AMT =%f \n PI = %e\nPOPULATION OF INDIA = %ld\n CODE =%c \n MESSAGE = %s",num,amt,pi,population_of_india,code,msg);

//Write a program to calculate the area of triangle using Hero's formula.

float a,b,c,area,S;
printf("\n\n\n Enter the lengths of the three sides of the triangle : ");
scanf("%f %f %f",&a,&b,&c);
S=(a +b +c)/2;
//sqrt is a mathematical function defined in math.h header file
area = sqrt(S*(S-a)*(S-b)*(S-c));
printf("\n Area = %f",area);
return 0;
}

C++ Online Compiler

Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C++ and start coding!

Read inputs from stdin

OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.

#include <iostream>
#include <string>
using namespace std;

int main() 
{
    string name;
    cout << "Enter name:";
    getline (cin, name);
    cout << "Hello " << name;
    return 0;
}

About C++

C++ is a widely used middle-level programming language.

  • Supports different platforms like Windows, various Linux flavours, MacOS etc
  • C++ supports OOPS concepts like Inheritance, Polymorphism, Encapsulation and Abstraction.
  • Case-sensitive
  • C++ is a compiler based language
  • C++ supports structured programming language
  • C++ provides alot of inbuilt functions and also supports dynamic memory allocation.
  • Like C, C++ also allows you to play with memory using Pointers.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition If-Else is used.

if(conditional-expression) {
   //code
}
else {
   //code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression){    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
......    
    
default:     
 code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  //code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while (condition) {  
// code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {  
 // code 
} while (condition);

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.

How to declare a Function:

return_type function_name(parameters);

How to call a Function:

function_name (parameters)

How to define a Function:

return_type function_name(parameters) {  
 // code
}