• Do some more difficult interpretation of Java code.
• Examine how arrays are passed to methods.

//imports
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Scanner;

public class InterpretJava {

     static int[] intArray = new int[100];
     static int openIntIndex = 0;
     
     static double[] doubleArray = new double[100];
     static int openDoubleIndex = 0;
     
     static String[] StringArray = new String[100];
     static int openStringIndex = 0;
     
     public static void main(String[] args) {
          readFile("inputFile.txt");
          writeFile("outputFile.txt");
     }
     
     public static void readFile( String inputFile){

          try{
               Scanner fileIn = new Scanner( new File(inputFile) );
          
               while( fileIn.hasNext() ){
                    
                    if( fileIn.hasNextDouble() ){
                         doubleArray[openDoubleIndex] = fileIn.nextDouble();
                         ++openDoubleIndex;
                         
                    } else if( fileIn.hasNextInt() ){
                         intArray[openIntIndex] =  fileIn.nextInt();
                         ++openIntIndex;
                         
                    } else {
                         StringArray[openStringIndex] = fileIn.next();
                         ++openStringIndex;
                         
                    }
               }
               
               fileIn.close();
          } catch( IOException e ){
               System.out.println("Error reading \""+inputFile+"\"\n"+e);
               System.exit(-1);
          }
          
     }
     
     public static void writeFile( String outputFile ){

          try{
               PrintWriter fileOut = new PrintWriter( new File(outputFile) );
               fileOut.print("[ ");
               for( int i = 0; i < openIntIndex; ++i ){
                    fileOut.print( intArray[i]+", " );
               }
               fileOut.println(" ]");
               
               fileOut.print("[ ");
               for( int i = 0; i < openDoubleIndex; ++i ){
                    fileOut.print( doubleArray[i]+", " );
               }
               fileOut.println(" ]");
               
               fileOut.print("[ ");
               for( int i = 0; i < openStringIndex; ++i ){
                    fileOut.print( StringArray[i]+", " );
               }
               fileOut.println(" ]");
               
               fileOut.close();
          } catch( IOException e ) {
               System.out.println("Error writing \""+outputFile+"\"\n"+e);
               System.exit(-1);
          }
     }
}

5 5.2 5g6.0 hello world! 100.0 7.5 11
3.1415962 pi  
1.6180339 phi 
2.71828 e
primeNumber( 0 )

1. Create a new R19 project in Eclipse and an associated class.
2. Copy the following code into R19:

   	public static void squareInt( int number ) { 
   
   	} 
   
   	public static void squareArray( int[] array ) { 
   	
   	} 
   
   	public static void main(String[] args) {
   
   		int mainInt = 12;
   		int mainArray[] = { 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610 };
   
   
   		System.out.println("Before: ");
   		System.out.println( mainInt );
   		System.out.println( "my array:"+ Arrays.toString( mainArray ) );
   
   		squareInt( mainInt );
   		squareArray( mainArray );
   
   		System.out.println("After: ");
   		System.out.println( mainInt );
   		System.out.println( Arrays.toString(mainArray) );
   
   	}
   

3. Implement the squareInt function, which computes the square of input parameter and stores the result back into the parameter.
4. Implement the squareArray function, which squares each element in the input array and stores the result back into the array.
5. Write a comment in your code explaining how the two methods differ with respect to passing parameters.