'a' was declared in this scope

#include <Stepper.h>


/*
  Stepper Motor Control - one revolution

  This program drives a unipolar or bipolar stepper motor.
  The motor is attached to digital pins 8 - 11 of the Arduino.

  The motor should revolve one revolution in one direction, then
  one revolution in the other direction.


  Created 11 Mar. 2007
  Modified 30 Nov. 2009
  by Tom Igoe

*/

#include <Stepper.h>

const int stepsPerRevolution = 64;  // change this to fit the number of steps per revolution
// for your motor

// initialize the stepper library on pins 8 through 11:
Stepper myStepper(stepsPerRevolution, 8, 9, 10, 11);

#define A 8
#define B 9
#define C 10
#define D 11

#define NUMBER_OF_STEPS_PER_REV 64

void setup() {
  // set the speed at 60 rpm:
  myStepper.setSpeed(60);
  // initialize the serial port:
  Serial.begin(9600);
  pinMode(A, OUTPUT);
  pinMode(B, OUTPUT);
  pinMode(C, OUTPUT);
  pinMode(D, OUTPUT);
}

void write() {
  digitalWrite(A, a);
  digitalWrite(B, b);
  digitalWrite(C, c);
  digitalWrite(D, d);
}

void onestep() {
  write(1, 0, 0, 0);
  delay(5);
  write(1, 1, 0, 0);
  delay(5);
  write(0, 1, 0, 0);
  delay(5);
  write(0, 1, 1, 0);
  delay(5);
  write(0, 0, 1, 0);
  delay(5);
  write(0, 0, 1, 1);
  delay(5);
  write(0, 0, 0, 1);
  delay(5);
  write(1, 0, 0, 1);
  delay(5);
}

void loop() {
  int i;
  i = 0;
  while (i < NUMBER_OF_STEPS_PER_REV) {
    onestep();
    i++;
  }
}

void loop() {
  // step one revolution  in one direction:
  Serial.println("clockwise");
  myStepper.step(stepsPerRevolution);
  delay(500);

  // step one revolution in the other direction:
  Serial.println("counterclockwise");
  myStepper.step(-stepsPerRevolution);
  delay(500);
}

Where? Copy that line. I don't find it.

sorry, it was suppose to be " 'a' as not declared in this scope"

The compiler does not lie

Why are you passing 4 values to a function that is declared as requiring no arguments ?

tryin to combine codes to et a step count for a turntable

Can you explain what this is supposed to do?

 write(1, 0, 0, 0);`

a is undefined and so is b, c and d, did you copy paste the code from elsewhere?

Would make sense. Anatomy of a function.

ok, so I was tryin to figure out how many steps my stepper motor as to take to turn my turntable 1 revolution. I was able to figure out another way.

I am attempting to build the cellphone 3d scanner found in thingiverse, its original design called for a standard servo modified for continuous rotation, which is not possible. So I modified the design to use a stepper motor. I was finally able to determine that my it takes 12 complete revolutions of my motor to complete one revolution of the scanning turntable.