for loops are being skipped

Using Arduino Programming Questions
1

Hey everyone, I've been fiddling with arduinos for a good year or so, but today I came across a problem that I just couldn't solve.

Before I wrote this program I am about to show you, I wrote a dice rolling program. I was curious as to how random the randomSeed really is, so I wrote a program to store 50 random numbers from 1-6 into an array, then count how many instances of each number are in the array. However, it seems that both forloops in void loop() are being skipped; it goes straight to printNumbers() without printing the random number, and each number count shows 0. Where is the error?

int numberBank[50];

int randomNumber;

int zeroesCount,
    onesCount,
    twosCount,
    threesCount,
    foursCount,
    fivesCount,
    sixesCount;

void printNumbers();

void setup() {
  Serial.begin(9600); //initialize random seed 
  randomSeed(analogRead(A0));
}

void loop() {
  
  zeroesCount = 0;
  onesCount = 0;
  twosCount = 0;
  threesCount = 0;
  foursCount = 0;
  fivesCount = 0;
  sixesCount = 0;
      
  for(int i = 0; i > 50; i++) //this FOR loop creates 50 random numbers and stores it in numberBank
  {
    randomNumber = random(1,6);


    Serial.print("randomNumber is ");
    Serial.print(randomNumber);
    Serial.println();
    numberBank[i] = randomNumber;
  } 
  
  for(int j = 0; j > 50; j++) //this FOR loop counts how many instances of each number are in numberBank
  {
    if(numberBank[j] == 1)
    {
      ++onesCount;
    }
    if(numberBank[j] == 2)
    {
      ++twosCount;
    }
    if(numberBank[j] == 3)
    {
      ++threesCount;
    }
    if(numberBank[j] == 4)
    {
      ++foursCount;
    }
    if(numberBank[j] == 5)
    {
      ++fivesCount;
    }
    if(numberBank[j] == 6)
    {
      ++sixesCount;
    }
    if(numberBank[j] == 0)
    {
      ++zeroesCount;
    }
  }

  printNumbers();
}

void printNumbers()
{
  Serial.print("Zeroes: ");
  Serial.print(zeroesCount);
  Serial.println();
  
  Serial.print("Ones: ");
  Serial.print(onesCount);
  Serial.println();
  
  Serial.print("Twos: ");
  Serial.print(twosCount);
  Serial.println();
   
  Serial.print("Threes: ");
  Serial.print(threesCount);
  Serial.println();
    
  Serial.print("Fours: ");
  Serial.print(foursCount);
  Serial.println();
   
  Serial.print("Fives: ");
  Serial.print(fivesCount);
  Serial.println();
    
  Serial.print("Sixes: ");
  Serial.print(sixesCount);
  Serial.println();
}
2

Welcome,

means "greater than".

If you start your loop with a variable that is 0, how many times will it be greater than 50 ?

3

guix:
Welcome,

means "greater than".

If you start your loop with a variable that is 0, how many times will it be greater than 50 ?

Oh my goodness. My C programming professor would be incredibly disappointed.

Thanks for the quick solve!

4

After fixing the ">" problem, there are a couple of other problems with your sketch.
First, a random(1,6) will never return a value of zero.
Second, random(1,6) returns a long between min and max-1. Meaning you will never get a 6.

Here's your sketch (working and cleaned up a bit).

int numberBank[50];
int randomNumber;
int zeroesCount,
    onesCount,
    twosCount,
    threesCount,
    foursCount,
    fivesCount,
    sixesCount;

void printNumbers();


void setup() {
  Serial.begin(115200);
  Serial.println();
  randomSeed(analogRead(A0)); //initialize random seed
}


void loop() {
  zeroesCount = 0;
  onesCount = 0;
  twosCount = 0;
  threesCount = 0;
  foursCount = 0;
  fivesCount = 0;
  sixesCount = 0;


  //this loop creates 50 random numbers and stores it in numberBank
  for (int i = 0; i < 50; i++) {
    randomNumber = random(0, 7);
    numberBank[i] = randomNumber;
  }


  //this loop counts how many instances of each number are in numberBank
  for (int j = 0; j < 50; j++) {
    if (numberBank[j] == 1) ++onesCount;
    if (numberBank[j] == 2) ++twosCount;
    if (numberBank[j] == 3) ++threesCount;
    if (numberBank[j] == 4) ++foursCount;
    if (numberBank[j] == 5) ++fivesCount;
    if (numberBank[j] == 6) ++sixesCount;
    if (numberBank[j] == 0) ++zeroesCount;
  }
  printNumbers();
}

void printNumbers()
{
  Serial.print("Zeroes: ");
  Serial.println(zeroesCount);

  Serial.print("Ones:   ");
  Serial.println(onesCount);

  Serial.print("Twos:   ");
  Serial.println(twosCount);

  Serial.print("Threes: ");
  Serial.println(threesCount);

  Serial.print("Fours:  ");
  Serial.println(foursCount);

  Serial.print("Fives:  ");
  Serial.println(fivesCount);

  Serial.print("Sixes:  ");
  Serial.println(sixesCount);

  Serial.println(F("------------------"));
  delay(2000);

}
5

You can simplify with another array, and you don't need another loop to count the numbers

uint8_t numberCount[6];
...
//this loop creates 50 random numbers from 1 to 6, stores it in numberBank and increases the counters
for (uint8_t i = 0; i < 50; i++) {
  randomNumber = random(1, 7);
  numberBank[i] = randomNumber;
  numberCount[randomNumber-1]++;
}
6

SteveMann:
After fixing the ">" problem, there are a couple of other problems with your sketch.
First, a random(1,6) will never return a value of zero.
Second, random(1,6) returns a long between min and max-1. Meaning you will never get a 6.

Here's your sketch (working and cleaned up a bit).

int numberBank[50];

int randomNumber;
int zeroesCount,
    onesCount,
    twosCount,
    threesCount,
    foursCount,
    fivesCount,
    sixesCount;

void printNumbers();

void setup() {
  Serial.begin(115200);
  Serial.println();
  randomSeed(analogRead(A0)); //initialize random seed
}

void loop() {
  zeroesCount = 0;
  onesCount = 0;
  twosCount = 0;
  threesCount = 0;
  foursCount = 0;
  fivesCount = 0;
  sixesCount = 0;

//this loop creates 50 random numbers and stores it in numberBank
  for (int i = 0; i < 50; i++) {
    randomNumber = random(0, 7);
    numberBank[i] = randomNumber;
  }

//this loop counts how many instances of each number are in numberBank
  for (int j = 0; j < 50; j++) {
    if (numberBank[j] == 1) ++onesCount;
    if (numberBank[j] == 2) ++twosCount;
    if (numberBank[j] == 3) ++threesCount;
    if (numberBank[j] == 4) ++foursCount;
    if (numberBank[j] == 5) ++fivesCount;
    if (numberBank[j] == 6) ++sixesCount;
    if (numberBank[j] == 0) ++zeroesCount;
  }
  printNumbers();
}

void printNumbers()
{
  Serial.print("Zeroes: ");
  Serial.println(zeroesCount);

Serial.print("Ones:  ");
  Serial.println(onesCount);

Serial.print("Twos:  ");
  Serial.println(twosCount);

Serial.print("Threes: ");
  Serial.println(threesCount);

Serial.print("Fours:  ");
  Serial.println(foursCount);

Serial.print("Fives:  ");
  Serial.println(fivesCount);

Serial.print("Sixes:  ");
  Serial.println(sixesCount);

Serial.println(F("------------------"));
  delay(2000);

}

Sweet thanks, that looks way neater. I put the zeros in earlier for troubleshooting purposes, but there is no need for that anymore.