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package class_notes;
import java.util.Arrays;
import java.util.Random;

/**
 *
 * @author randycires
 */
public class Class_Notes {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
    //---------------------------------------------------------        
    // Working with Arrays
    //--------------------------------------------------------- 
            System.out.println("---------------------------------------------------------");
            System.out.println(" Working with Arrays ");
            System.out.println("---------------------------------------------------------");
        double[]values = new double [10];
        //The above line creates an array of type double with length 10.
        System.out.println("Essentially all this for loop does is print the values of the array values");
        for (int i = 0; i<values.length; i++){
            System.out.println("values["+i+"]="+values[i]);
        }
      
            
    //----------------------------------
    // Arrays Reference  
    //----------------------------------
      System.out.println("\n");
      System.out.println("---------------------------------------------------------");
      System.out.println("These values are to show what referencing an array does:");
      System.out.println("---------------------------------------------------------");

       
        
        int []scores={10,9,3,5,8};
        //You can create an array like this too. This format allows you to 
        //insert the elements you want in each index. 
        
        int[]otherScores=scores;
        //This is a reference. I just set them equal to each other. If I change 
        //one I change both.
        
        otherScores[0]=100;
        //this just set both the first element of arrays: scores and otherScores
        //to 100.
        
        System.out.println("scores[0]="+scores[0]);
        System.out.println("otherScores[0]="+otherScores[0]);
        
    //----------------------------------
    // Copying an Array   
    //---------------------------------- 
        System.out.println("\n");
        System.out.println("-----------------------------------");
        System.out.println("Now copying an array is different");
        System.out.println("-----------------------------------");
        //this is the code for copying an array
        otherScores=Arrays.copyOf(scores,scores.length);
        
        //Now my questions are:
        /*// the copyOf function what are its parameters? 
        I understand that scores is essentially just copying the values in the array. 
        Is scores.length here to assure that the arrays are the same size?
        Previously, otherScores was created as a reference to scores how does this copy impact the global scope?
        By using "Arrays.copyOf" the previous reference to scores is replaced by becoming a copy.It's overwritten*/
        
        otherScores[0]=200;
        //Note you reassign otherScores[0] to 200 here. 
        //If you didn't the copy would return scores[0] and otherScores[0] as the same "100" value.
        System.out.println("If coded properly this should return 100 and 200 respectively."
        +"scores was left alone and otherScores was changed but, otherScores is still based on scores.");
        System.out.println("scores[0]="+scores[0]);
        System.out.println("otherScores[0]="+otherScores[0]);
        System.out.println("Testing that a copy and not a reference was done:");
        
        System.out.println("scores[1]="+scores[1]);
        System.out.println("otherScores[1]="+otherScores[1]);
        //Both values should be 9
    
    //----------------------------------
    // Adding elements of an Array    
    //---------------------------------- 
        System.out.println("\n");
        System.out.println("---------------------------------------------------------");
        System.out.println(" Add Scores");
        System.out.println("---------------------------------------------------------");
        
        //This for loop should print out all the elements of the array "scores" like previously in the first example.
        for (int i = 0; i<scores.length; i++){
        System.out.println("scores["+i+"]="+scores[i]);
        }
        //totalScore is a variable declared to hold the sum of all the elements in the array scores.
        int totalScore=0;
        
        for(int i=0; i<scores.length ;i++){
            totalScore=totalScore+scores[i];
        }
        System.out.println("Total Score = " + totalScore);
            
    //----------------------------------
    // The Enhanced for Loop   
    //----------------------------------
        System.out.println("\n");
        System.out.println("---------------------------------------------------------");
        System.out.println(" The Enhanced For Loop");
        System.out.println("---------------------------------------------------------");
        
        int[]scores2={1,2,3,4,5,6,7,8};
        System.out.println("Without using an enhanced For Loop:");
        for(int i=0;i<scores2.length;i++){
            System.out.println("scores2["+i+"]="+scores2[i]);
        }
        System.out.println("---------------------------------------------------------");
        System.out.println("Using an enhanced For Loop:");
        int i=0;// why this int??
        for(int currentInt:scores2){
            System.out.println("scores2["+i+"]="+currentInt);
            i++;// including this here subverts the zero's for the index.
        }
        //A good use of the for loop. This adds all the elements in the array scores2
        int totalSum=0;
        for(int currentInt:scores2){
            totalSum=totalSum+currentInt;
        }
        System.out.println("\n \n totalSum="+totalSum);
    }
    
            
            

        
        
        
        
}