user32169: I am trying to store a set of functions with different parameter in an array. When the code enters the function songlearn with tune==1 I want the functions with set parameters to be stored in the array without executing. What am I doing wrong? Here's my code:
const int x=100;
int (*SongSeq[x])();
int note[x];
int playNote(int midi, int row, int col, int len, bool short_led = false);
void songlearn(int tune);
int tune;

void songlearn (int tune){
  if (tune==1){ 
    state=1;
   lcd.clear();
  lcd.setCursor(4,0); 
  lcd.print("Learning Song :");// Print a message to the LCD.
  lcd.setCursor(1, 1);
  lcd.print(menuP1);
// if (songpage==1){
// if (BackState==HIGH){//leaving song
//     posP=0;
//     Page=2; 
//    Play(posP);
//    }
// }
  //Plays Mary Had a Little Lamb on a loop at 145 BPM
//Bar 1
SongSeq[0]= playNote(0x40, 3, 1, 414); //Quarter note: E
note[0]=0x40;
SongSeq[1]=playNote(0x3e, 2, 4, 414); //Quarter note: D
note[1]=0x3e;
SongSeq[2]=playNote(0x3c, 2, 2, 414); //Quarter note: C
note[2]=0x3c;
SongSeq[3]=playNote(0x3e, 2, 4, 414); //Quarter note: D
note[3]=0x3e;
//Bar 2
SongSeq[4]=playNote(0x40, 3, 1, 414,1); //Quarter note: E
note[4]=0x40;
SongSeq[5]=playNote(0x40, 3, 1, 414,1); //Quarter note: E
note[5]=0x40;
SongSeq[6]=playNote(0x40, 3, 1, 828,1); //Half note: E
note[6]=0x40;
//Bar 3
SongSeq[7]=playNote(0x3e, 2, 4, 414,1); //Quarter note: D
note[7]=0x3e;
SongSeq[8]=playNote(0x3e, 2, 4, 414,1); //Quarter note: D 
note[8]=0x3e;
SongSeq[9]=playNote(0x3e, 2, 4, 828,1); //Half note: D
note[9]=0x3e;
//Bar 4
SongSeq[10]=playNote(0x40, 3, 1, 414); //Quarter note: E
note[10]=0x40;
SongSeq[11]=playNote(0x43, 3, 4, 414,1); //Quarter note: G
note[11]=0x43;
SongSeq[12]=playNote(0x43, 3, 4, 828,1); //Half note: G
note[12]=0x43;
//Bar 5
SongSeq[13]=playNote(0x40, 3, 1, 414); //Quarter note: E
note[13]=0x40;
SongSeq[14]=playNote(0x3e, 2, 4, 414); //Quarter note: D
note[14]=0x3e;
SongSeq[15]=playNote(0x3c, 2, 2, 414); //Quarter note: C
note[15]=0x3c;
SongSeq[16]=playNote(0x3e, 2, 4, 414); //Quarter note: D
note[16]=0x3e;
//Bar 6
SongSeq[17]=playNote(0x40, 3, 1, 414,1); //Quarter note: E
note[17]=0x40;
SongSeq[18]=playNote(0x40, 3, 1, 414,1); //Quarter note: E
note[18]=0x40;
SongSeq[19]=playNote(0x40, 3, 1, 414,1); //Quarter note: E
note[19]=0x40;
SongSeq[20]=playNote(0x40, 3, 1, 414,1); //Quarter note: E
note[20]=0x40;
//Bar 7
SongSeq[21]=playNote(0x3e, 2, 4, 414,1); //Quarter note: D
note[21]=0x3e;
SongSeq[22]=playNote(0x3e, 2, 4, 414,1); //Quarter note: D
note[22]=0x3e;
SongSeq[23]=playNote(0x40, 3, 1, 414); //Quarter note: E
note[23]=0x40;
SongSeq[24]=playNote(0x3e, 2, 4, 414); //Quarter note: D
note[24]=0x3e;
//Bar 8
SongSeq[25]=playNote(0x3c, 2, 2, 1656); //Whole note: C
note[25]=0x3c;

//End song
  }
 }
 int playNote(int midi, int row, int col, int len, bool short_led = false)
{
    int len1, len2;
    if (short_led) {
        len1 = len * 3 / 4;
        len2 = len * 1 / 4;
    } else {
        len1 = len;
        len2 = 0;
    }
    noteOn(0x90, midi, 100);
    digitalWrite(LedR[row], HIGH);
    digitalWrite(LedC[col], LOW);
    delay(len1);
    digitalWrite(LedR[row], LOW);
    digitalWrite(LedC[col], HIGH);
    delay(len2);
    noteOff(0x90, midi, 0);
}


user313: Calling or entering a function means executing it -- that is just how the language is defined. A 'function' is not a construct you can manage, i.e., store or otherwise mess-with (technical term!) in the ways you might do with other kinds of data. But:
You can store a function's address (i.e., a pointer to the function) and use the pointer to call the function, and you can store its parameters just as you would store any data. So, if I understand correctly what you want to do, try something like this crude outline based on my quick read of your code. It uses stored function pointers and song-numbers and shows how to call one of those functions with the associated, stored song number as a parameter:
// Ptr to a function and a song number
typedef struct {
   void (*pfunc)(int tune);
   int tuneNum;
} SONG_T;

#define COUNT 12

void songlearn(int);
void othersongfunc(int);
// void moresongfunctions(int);
// void moresongfunctions(int);

// Table of songs & functions:
SONG_T Songs[COUNT] = {
   {songlearn, 2},
   {othersongfunc, 1},
   {songlearn, 7},
   {othersongfunc, 3},
   // etc
};


void songlearn(int)
{
    ;   // does whatever it does
}

void othersongfunc(int)
{
    ;   // does whatever it does
}

void somefunc(uint8_t whichSong)
{
   if( whichSong < COUNT )
      (*Songs[whichSong].pfunc)(Songs[whichSong].tuneNum);
}

void setup(void)
{
   somefunc(3);
}

void loop(void)
{
   ;
}


user10794: What you have done will certainly call the function. Since it is always the same function, just store the arguments into an array. Something like this:
const int COUNT = 100;

struct 
  {
  int midi;
  int row;
  int col; int len;
  bool short_led;
  } notes [COUNT] = {
  { 0x40, 3, 1, 414 },  //Quarter note: E
  { 0x3e, 2, 4, 414 },  //Quarter note: D
  { 0x3c, 2, 2, 414 },  //Quarter note: C

  // and so on
  };

int playNote(int midi, int row, int col, int len, bool short_led = false);

void setup() 
  {
  // put your setup code here, to run once:
  }

void loop() 
  {
  for (int i = 0; i < COUNT; i++)
    {
    if (notes [i].midi)
      playNote (notes [i].midi, notes [i].row, notes [i].col, 
                notes [i].len, notes [i].short_led);
    }
  }

int playNote(int midi, int row, int col, int len, bool short_led)
{
    int len1, len2;
    if (short_led) {
        len1 = len * 3 / 4;
        len2 = len * 1 / 4;
    } else {
        len1 = len;
        len2 = 0;
    }
    noteOn(0x90, midi, 100);
    digitalWrite(LedR[row], HIGH);
    digitalWrite(LedC[col], LOW);
    delay(len1);
    digitalWrite(LedR[row], LOW);
    digitalWrite(LedC[col], HIGH);
    delay(len2);
    noteOff(0x90, midi, 0);
}



yeah but i want to be able to store the function in an array with the set parameters

Do you? I wonder why.
Anyway, you can do that by making an array of lambda functions like this:
const int COUNT = 100;

int playNote(int midi, int row, int col, int len, bool short_led = false);

void (*SongSeq[COUNT])() = 
 {
 [] { playNote(0x40, 3, 1, 414); } ,
 [] { playNote(0x3e, 2, 4, 414); } ,
 [] { playNote(0x3c, 2, 2, 414); } ,
 [] { playNote(0x3e, 2, 4, 414); } ,

 // ... and so on 

 };

void setup() 
  {
  Serial.begin (115200);
  }

void loop() 
  {
  for (int i = 0; i < COUNT; i++)
    {
    if (SongSeq [i])
      SongSeq [i] ();
    }
  }

int playNote(int midi, int row, int col, int len, bool short_led)
{
  Serial.print ("Playing note ");
  Serial.println (midi);
  delay (100);
}


32169: <p>I am trying to store a set of functions with different parameter in an array. When the code enters the function <code>songlearn</code> with <code>tune==1</code> I want the functions with set parameters to be stored in the array without executing. What am I doing wrong? Here's my code:</p>

<pre><code>const int x=100;
int (*SongSeq[x])();
int note[x];
int playNote(int midi, int row, int col, int len, bool short_led = false);
void songlearn(int tune);
int tune;

void songlearn (int tune){
  if (tune==1){ 
    state=1;
   lcd.clear();
  lcd.setCursor(4,0); 
  lcd.print("Learning Song :");// Print a message to the LCD.
  lcd.setCursor(1, 1);
  lcd.print(menuP1);
// if (songpage==1){
// if (BackState==HIGH){//leaving song
//     posP=0;
//     Page=2; 
//    Play(posP);
//    }
// }
  //Plays Mary Had a Little Lamb on a loop at 145 BPM
//Bar 1
SongSeq[0]= playNote(0x40, 3, 1, 414); //Quarter note: E
note[0]=0x40;
SongSeq[1]=playNote(0x3e, 2, 4, 414); //Quarter note: D
note[1]=0x3e;
SongSeq[2]=playNote(0x3c, 2, 2, 414); //Quarter note: C
note[2]=0x3c;
SongSeq[3]=playNote(0x3e, 2, 4, 414); //Quarter note: D
note[3]=0x3e;
//Bar 2
SongSeq[4]=playNote(0x40, 3, 1, 414,1); //Quarter note: E
note[4]=0x40;
SongSeq[5]=playNote(0x40, 3, 1, 414,1); //Quarter note: E
note[5]=0x40;
SongSeq[6]=playNote(0x40, 3, 1, 828,1); //Half note: E
note[6]=0x40;
//Bar 3
SongSeq[7]=playNote(0x3e, 2, 4, 414,1); //Quarter note: D
note[7]=0x3e;
SongSeq[8]=playNote(0x3e, 2, 4, 414,1); //Quarter note: D 
note[8]=0x3e;
SongSeq[9]=playNote(0x3e, 2, 4, 828,1); //Half note: D
note[9]=0x3e;
//Bar 4
SongSeq[10]=playNote(0x40, 3, 1, 414); //Quarter note: E
note[10]=0x40;
SongSeq[11]=playNote(0x43, 3, 4, 414,1); //Quarter note: G
note[11]=0x43;
SongSeq[12]=playNote(0x43, 3, 4, 828,1); //Half note: G
note[12]=0x43;
//Bar 5
SongSeq[13]=playNote(0x40, 3, 1, 414); //Quarter note: E
note[13]=0x40;
SongSeq[14]=playNote(0x3e, 2, 4, 414); //Quarter note: D
note[14]=0x3e;
SongSeq[15]=playNote(0x3c, 2, 2, 414); //Quarter note: C
note[15]=0x3c;
SongSeq[16]=playNote(0x3e, 2, 4, 414); //Quarter note: D
note[16]=0x3e;
//Bar 6
SongSeq[17]=playNote(0x40, 3, 1, 414,1); //Quarter note: E
note[17]=0x40;
SongSeq[18]=playNote(0x40, 3, 1, 414,1); //Quarter note: E
note[18]=0x40;
SongSeq[19]=playNote(0x40, 3, 1, 414,1); //Quarter note: E
note[19]=0x40;
SongSeq[20]=playNote(0x40, 3, 1, 414,1); //Quarter note: E
note[20]=0x40;
//Bar 7
SongSeq[21]=playNote(0x3e, 2, 4, 414,1); //Quarter note: D
note[21]=0x3e;
SongSeq[22]=playNote(0x3e, 2, 4, 414,1); //Quarter note: D
note[22]=0x3e;
SongSeq[23]=playNote(0x40, 3, 1, 414); //Quarter note: E
note[23]=0x40;
SongSeq[24]=playNote(0x3e, 2, 4, 414); //Quarter note: D
note[24]=0x3e;
//Bar 8
SongSeq[25]=playNote(0x3c, 2, 2, 1656); //Whole note: C
note[25]=0x3c;

//End song
  }
 }
 int playNote(int midi, int row, int col, int len, bool short_led = false)
{
    int len1, len2;
    if (short_led) {
        len1 = len * 3 / 4;
        len2 = len * 1 / 4;
    } else {
        len1 = len;
        len2 = 0;
    }
    noteOn(0x90, midi, 100);
    digitalWrite(LedR[row], HIGH);
    digitalWrite(LedC[col], LOW);
    delay(len1);
    digitalWrite(LedR[row], LOW);
    digitalWrite(LedC[col], HIGH);
    delay(len2);
    noteOff(0x90, midi, 0);
}
</code></pre>
 313: <p>Calling or entering a function <em>means</em> executing it -- that is just how the language is defined. A 'function' is not a construct you can manage, i.e., store or otherwise mess-with (technical term!) in the ways you might do with other kinds of data. But:</p>

<p>You <em>can</em> store a function's address (i.e., a pointer to the function) and use the pointer to call the function, and you can store its parameters just as you would store any data. So, if I understand correctly what you want to do, try something like this crude outline based on my quick read of your code. It uses stored function pointers and song-numbers and shows how to call one of those functions with the associated, stored song number as a parameter:</p>

<pre><code>// Ptr to a function and a song number
typedef struct {
   void (*pfunc)(int tune);
   int tuneNum;
} SONG_T;

#define COUNT 12

void songlearn(int);
void othersongfunc(int);
// void moresongfunctions(int);
// void moresongfunctions(int);

// Table of songs &amp; functions:
SONG_T Songs[COUNT] = {
   {songlearn, 2},
   {othersongfunc, 1},
   {songlearn, 7},
   {othersongfunc, 3},
   // etc
};


void songlearn(int)
{
    ;   // does whatever it does
}

void othersongfunc(int)
{
    ;   // does whatever it does
}

void somefunc(uint8_t whichSong)
{
   if( whichSong &lt; COUNT )
      (*Songs[whichSong].pfunc)(Songs[whichSong].tuneNum);
}

void setup(void)
{
   somefunc(3);
}

void loop(void)
{
   ;
}
</code></pre>
 10794: <p>What you have done will certainly call the function. Since it is always the same function, just store the <em>arguments</em> into an array. Something like this:</p>

<pre><code>const int COUNT = 100;

struct 
  {
  int midi;
  int row;
  int col; int len;
  bool short_led;
  } notes [COUNT] = {
  { 0x40, 3, 1, 414 },  //Quarter note: E
  { 0x3e, 2, 4, 414 },  //Quarter note: D
  { 0x3c, 2, 2, 414 },  //Quarter note: C

  // and so on
  };

int playNote(int midi, int row, int col, int len, bool short_led = false);

void setup() 
  {
  // put your setup code here, to run once:
  }

void loop() 
  {
  for (int i = 0; i &lt; COUNT; i++)
    {
    if (notes [i].midi)
      playNote (notes [i].midi, notes [i].row, notes [i].col, 
                notes [i].len, notes [i].short_led);
    }
  }

int playNote(int midi, int row, int col, int len, bool short_led)
{
    int len1, len2;
    if (short_led) {
        len1 = len * 3 / 4;
        len2 = len * 1 / 4;
    } else {
        len1 = len;
        len2 = 0;
    }
    noteOn(0x90, midi, 100);
    digitalWrite(LedR[row], HIGH);
    digitalWrite(LedC[col], LOW);
    delay(len1);
    digitalWrite(LedR[row], LOW);
    digitalWrite(LedC[col], HIGH);
    delay(len2);
    noteOff(0x90, midi, 0);
}
</code></pre>

<hr>

<blockquote>
  <p>yeah but i want to be able to store the function in an array with the set parameters</p>
</blockquote>

<p>Do you? I wonder why.</p>

<p>Anyway, you can do that by making an array of lambda functions like this:</p>

<pre><code>const int COUNT = 100;

int playNote(int midi, int row, int col, int len, bool short_led = false);

void (*SongSeq[COUNT])() = 
 {
 [] { playNote(0x40, 3, 1, 414); } ,
 [] { playNote(0x3e, 2, 4, 414); } ,
 [] { playNote(0x3c, 2, 2, 414); } ,
 [] { playNote(0x3e, 2, 4, 414); } ,

 // ... and so on 

 };

void setup() 
  {
  Serial.begin (115200);
  }

void loop() 
  {
  for (int i = 0; i &lt; COUNT; i++)
    {
    if (SongSeq [i])
      SongSeq [i] ();
    }
  }

int playNote(int midi, int row, int col, int len, bool short_led)
{
  Serial.print ("Playing note ");
  Serial.println (midi);
  delay (100);
}
</code></pre>
