for loop Arduino/C

Question

My aim is to create a for loop that iterates through numbers and once it reaches the maximum, it stops printing. So far I managed to create a piece of code that stops printing the x but it keeps printing zeroes. How can I stop Serial.print() function to be executed once the iteration reached the maximum value?

int x;
boolean f = false;

void setup(){
  Serial.begin(9600);
}

void loop(){
  for(x=0;x<8;x++){
    Serial.println(x);
    delay(300);
    if(x==7){
      f = true;
    }
    if(f){
      break;
    }
  }
}

Answer 1

Something like below should serve. Btw, I like to name my vars something meaningful to avoid potential confusion and make the code more intelligible.

(In general you are better off posting questions to the Arduino forum. More traffic and more knowledgeable/helpful people == more likelihood of getting an answer.)

int current;
int limit;
boolean complete;

void setup(){
  Serial.begin(9600);

  current = 0;
  limit = 8;
  complete = false;
}

void loop(){

  if (!complete){
    while (true){
      Serial.println(current);
      current++;
      if (current >= limit){
        complete = true;
        break;
      }
      delay(300);
    }
  }
}

Answer 2

The key is the word loop - that function is called repetitively!

If you want something to happen once, do it in setup(), or (as another answer suggests), have a flag to keep track of the fact that you've done it already.

Another way (since x is global) would be:

void loop() {
  if (x < 8) { 
     Serial.println(x);
     x++;
   }
}

or, getting rid of the global variable:

void loop() {
  static int x = 0;
  if (x < 8) { 
     Serial.println(x);
     x++;
   }
}

Answer 3

int x;
boolean f = false;

void setup(){
  Serial.begin(9600);
}

Very similar to your code, just put the print statement in the if statement and you're set.

void loop(){
  for(x=0;x<8;x++){
    if(!f) {
      Serial.println(x);
    }
    delay(300);
    if(x==7){
      f = true;
    }
  }
}