create programme by using array's

Projects Programming
1

Hello .
I am trying to learn how to use array.

For these:( see Attach)
1.I am using Arduino uno
2.breadboard
3. Three soil moistures sensors connect to A0,A1 ,A2

I am using as an example the following code:

#include <SoftwareSerial.h>
int readPin0 = A0;
int readPin1 = A1;
int readPin2 = A2;
int readValue0 = A0;
int readValue1 = A1;
int readValue2 = A2;

void setup() {
  Serial.begin(9600);  
}
void loop() {
  readValue0 = analogRead(readPin0);     
  delay(1000);
  Serial.print("sensor0 = " );
  Serial.println(readValue0);

   readValue1 = analogRead(readPin1);     
  delay(1000);
  Serial.print("sensor1 = " );
  Serial.println(readValue1);

   readValue2 = analogRead(readPin2);     
  delay(1000);
  Serial.print("sensor2 = " );
  Serial.println(readValue2);
}

which is working.

I am trying to change the previous code by using arrows

and i change it to the follow:

int array[] = {A0, A1, A2};
int numSensors = 3;

void setup() {
    for (int i=0; i<numSensors; i++);
      pinMode(array[],INPUT);
      for (int i=0; i<numSensors; i++)
  analogRead(array[i],LOW);
  
}

void loop() {
  delay(1000);
  for (int i=0; i<numSensors; i++)
  analogRead(array[i],HIGH);
  delay(1000);
}
for (int i=0; i<numSensors; i++)
  analogRead(array[i],LOW);
}

When i am trying to compile arduino says :
exit status 1
expected primary-expression before ']' token for pinMode(array[],INPUT);

What i exacluy do i had make wrong ?
Any Help willbe appreciate.

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2

pinMode(array[i],INPUT);

3 
  for (int i = 0; i < numSensors; i++);

What's that semicolon doing at the end of the line ?
Apart, that is, from being the only code executed by the for loop

   analogRead(array[i], LOW);

Strange use of analogRead() (3 times in the code)

4 
int readPin0 = A0;
int readPin1 = A1;
int readPin2 = A2;
int readValue0 = A0;
int readValue1 = A1;
int readValue2 = A2;

You have two collections of scalar variables with decent names.

int array[] = {A0, A1, A2};

You replace them with one array with a really stupid name. How is THAT an improvement?

You obviously need TWO arrays. The names really should be readPins and readValues.

5

To me, good variable (attribute) names are nouns and function (method) names are verbs. I'd use something that better conveys what you're doing:

int sensorsUsed = 3;

int sensorPin[] = {A0, A1, A2};
int sensorValue[3];

// bunch of code...

   for (int i = 0; i < sensorsUsed; i++) {
      sensorValue[i] = analogRead(sensorPin[i]);
   }

I would also get into the habit of always using braces with for, if, while statement blocks even if only a single statement is controlled by the statement block. It lessens likelihood of the "dangling semicolon" error you had in your code, plus you may need to put a debug Serial.print() statement in the block at some time anyway.