// need to include the SD library
#define SD_ChipSelectPin 4 //connect pin 4 of arduino to cs pin of sd card
 //Arduino library for asynchronous playback of PCM/WAV files
 //  need to include the SPI library

TMRpcm tmrpcm; // create an object for use in this sketch
int temp=1;
int pp=5;
int next=6;
int prev=7;
void setup()
{ 
 pinMode(pp,INPUT_PULLUP);
 pinMode(next,INPUT_PULLUP);
 pinMode(prev,INPUT_PULLUP);
 
 tmrpcm.speakerPin = 9; //5,6,11 or 46 on Mega, 9 on Uno, Nano, etc
 Serial.begin(9600);
 if (!SD.begin(SD_ChipSelectPin)) // returns 1 if the card is present
 {
  Serial.println("SD fail");
  return;
 }

 tmrpcm.setVolume(5); //
 tmrpcm.play("song1.wav"); //the sound file "song" will play each time the arduino powers up, or is reset
                          //try to provide the file name with extension
                     
}


void loop()
{  
  while(digitalRead(pp)==0 || digitalRead(next)==0 || digitalRead(prev)==0)
  {
    if(digitalRead(pp)==0)
    {
      tmrpcm.pause();
      while(digitalRead(pp)==0);
      delay(200);
    }
    else if(digitalRead(next)==0)
    {
      if(temp<4)//temp should be lesser than no. of songs 
      temp=temp+1;
      while(digitalRead(next)==0);
      delay(200);
      song();
    }
    else if(digitalRead(prev)==0)
    {
      if(temp>1)
      temp=temp-1;
      while(digitalRead(prev)==0);
      delay(200);
      song();
    }
  }
}

void song (void)
{
  if(temp==1)
  {
    tmrpcm.play("Song1.wav");  
  }
  else if(temp==2)
  {
    tmrpcm.play("Song2.wav");  
  }
  else if(temp==3)
  {
    tmrpcm.play("Song3.wav");  
  }
  else if(temp==4)
  {
    tmrpcm.play("Song4.wav");  
  }
}

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
}