//Purpose:compute a heart beat training zone for your age of interest
import java.util.*;
public class TrainingZone{
//main():application entry point
public static void main(string[]args){
//defining constants
	final double LOW_ZONE_MULTIPLIER=0.65;
	final double HIGH_ZONE_MULTIPLIER=0.80;
	final double BASE_RATE=220.0;
 
	//displaying legend(step1)
	System.out.println("Heart beat estimator");
	 //get person's characteristics
	System.out.print("Enter age(years): ");
	double age = stdin.nextDouble();
 
	//perform trainingZone
                double trainingzone=HIGH_ZONE_MULTIPLIER*(BASE_RATE-ageOf Interest);
   	double trainingzone=LOW_ZONE_MULTIPLIER*(BASE_RATE-ageOf Interest); 	//display result
	System.out.println("Suggested heart beat training zone for");
	System.out.println("a fit person"+"age of interest"+"years with normal");
	System.out.println("heart rate is"+"low BeatRate"+"to");
	System.out.println ("high BeatRate"+"beats per minute");  
  }
}
 
 
it gives    ')'expected  errors on 
   double trainingzone=HIGH_ZONE_MULTIPLIER*(BASE_RATE-ageOf Interest);
   double trainingzone=LOW_ZONE_MULTIPLIER*(BASE_RATE-ageOf Interest);

Scanner stdin = new Scanner(System.in);

public class UsingVariables{
 
   public static void main(String[] args){
     int aNewVariable = 0; //creates 'aNewVariable' & initializes it to 0.
     //creates 'a_Different_Variable' & doesn't initialize it.
     int a_Different_Variable; 
 
     System.out.println(aNewVariable); //This will print 0
 
    //We didn't initialize the variable & can't be sure what this prints
     System.out.println(a_Different_Variable); 
 
     //Not allowed. a_Different_Variable already exists!
     int a_Different_Variable = 5; 
 
     //This initializes a_Different_Variable to 5.
     a_Different_Variable = 5; 
 
     System.out.println(a_Different_Variable); //This will print 5.
   }
}