reading variables class to class

[paul spriesterbach]

Hi I just want to be able to read type and weight in the Letter class I created (I created read out messages to check in the Letter class). I am able to read it with in the Mail class. Any help and/or advise with this simple problem is greatly appreciated!

///////////////////////////////////////////////////////////////////////////////

package org.mailprice.postage;

import java.util.Scanner;

public class Mail {
	
static Letter letter;
	
	// Main Method 
	public static void main(String[] args) 
	{
		inputType();
		inputWeight();
		letter = new Letter();
		letter.LetterPrice();
		


	} 

	
	//Method for inputting letter type and weight
	public static int inputType ()
	{
		Scanner input = new Scanner(System.in);
		
		int type;

		
		System.out.print("If sending a Letter Enter: 1\nIf sending a Large Envelope Enter: 2\nType:");
		type=input.nextInt();
		
		
		//check
		System.out.print("\nType is " + type);
		return type;
	}
	
	public static double inputWeight ()
	{
		Scanner input = new Scanner(System.in);
		
		double weight;
		
		System.out.print("\nEnter Weight:");
		weight= input.nextDouble();
		
		//check
		System.out.print("Weight is " + weight );
		return weight;
	}
	
}

/////////////////////////////////////////////////////////////////////////////////////////////////////////////

package org.mailprice.postage;
//class to figure out letter price
public class Letter {
	
	
	//check
	public void LetterPrice()
	{
		System.out.print( "\nYou made it to LetterPrice Class");
		System.out.print("\nType is " + type);
		System.out.print("Weight is " + weight );
	}

}

[Scott Winterbourne]

Hi Paul, welcome to the Ranch!

There are several ways you can pass the type and weight values to your Letter class.

One way is to pass them in the constructor. Where you call new Letter(); you can pass the values here as parameters. You will then have to declare a custom constructor in the Letter class.

Another way is to pass the values into the LetterPrice() method as shown below:

letter.LetterPrice(type, weight);

You will have to modify the LetterPrice() method definition in the Letter class to accept these 2 parameters and then use them inside the method.

[Campbell Ritchie]

Welcome again

Why have you got all static methods in the Mail class? Why is the letter marked static?

[paul spriesterbach]

Campbell Ritchie wrote:Welcome again

Why have you got all static methods in the Mail class? Why is the letter marked static?

Because I am a noob and I am trying to follow my text book examples to do this problem

[paul spriesterbach]

paul spriesterbach wrote:

Campbell Ritchie wrote:Welcome again

Why have you got all static methods in the Mail class? Why is the letter marked static?

Because I am a noob and I am trying to follow my text book examples to do this problem

Let me go back and redo the code after I read up a bit more. Ive figured some stuff out now

[Campbell Ritchie]

Text book? Which one?

If the letter is marked static, then there is only one letter at any one time. If it is not static, then each Mail object has its own letter.

[paul spriesterbach]

Campbell Ritchie wrote:Text book? Which one?

If the letter is marked static, then there is only one letter at any one time. If it is not static, then each Mail object has its own letter.

We are using the Deitel 9th edition one for the class im in. Is there any learning material you would recommend that I can use to supplement what I am using in the class, I dont want to just get a good grade I really want to understand everything.

[Campbell Ritchie]

Deitel? Early objects edition or late objects edition? I would have thought neither version of Deitel would have a static field like that.

[paul spriesterbach]

Campbell Ritchie wrote:Deitel? Early objects edition or late objects edition? I would have thought neither version of Deitel would have a static field like that.

title is Java how to program.... ya I have changed my code considerably, ill post it a little later

[paul spriesterbach]

Ok this is what I have so far. Im still trying to figure out the best way to send these values over to the LetterPrice class and use them in the two method 'check type' and 'calculate price' place holders I have. Any help is much appreciated, thank you!

It doesnt like my

LetterPrice myLetterPrice = new LetterPrice(theType, theWeight);

any insight into why?

package org.mailprice.postage;

import java.util.Scanner;

public class Mail 
{
	
	// Main Method 
	public static void main(String[] args) 
	{
		
		//create Scanner to obtain input
		Scanner input = new Scanner(System.in);
		
		//Create a LetterPrice object
		LetterPrice myLetterPrice = new LetterPrice(theType, theWeight);
		
		//prompt to read in type
		System.out.println("Please enter Letter or Envelope:");
		String theType = input.nextLine();
		
		
		/*myType.setType(theType);
		System.out.println();*/
		
		//prompt to read in Weight
		System.out.println("Please enter weight:");
		float theWeight = input.nextFloat();
		
		//send theType and theWeight to LetterPrice
		myLetterPrice.setType(theType);
		myLetterPrice.setWeight(theWeight);
	} 
}
	

package org.mailprice.postage;

//import java.util.*;
//import java.io.*;

public class LetterPrice 
{

//constructor
	public LetterPrice(String theType, float theWeight )
	{
		this.weight = theWeight;
		this.type = theType;
	}
	
//Method to Check type
	

//Method to calculate price 	
	
	
//getter for Weight
	public float getWeight() 
	{
		return this.weight;
	}
//setter for Weight
	public void setWeight(float weight) 
	{
		this.weight = weight;
	}
//getter for Type
	public String getType() 
	{
		return this.type;
	}
//setter for Type
	public void setType(String type) 
	{
		this.type = type;
	}
//Initialize	
	private float weight;
	private String type;
	
}

[Scott Winterbourne]

The "theType" and "theWeight" variables you used in the main() method have not been declared or initialized with values.

You will need to declare them as data types (i.e. String, float, etc.) and then assign values to them before you can pass them into the

new ListPrice(theType, theWeight)

constructor.

[Scott Winterbourne]

If you are going to pass the values into the constructor like you are trying on line 16, you would need to move line 16 below line 28 so both variables have been declared and initialized with the values from the user input.

You are also calling set methods for these values on line 31 which is redundant. You don't need to pass the values in the custructor as well as call the set methods. Here you can do one or the other to get the values into the LetterPrice Object.

Either you can move line 16 to line 29 and get rid of lines 31 and 32 OR on line 16 you can just call the default constructor passing no parameters "new LetterPrice()" and then use the set methods on lines 31 and 32.

[paul spriesterbach]

Scott Winterbourne wrote:The "theType" and "theWeight" variables you used in the main() method have not been declared or initialized with values. That should work now? Edit: ok I removed redundant code

You will need to declare them as data types (i.e. String, float, etc.) and then assign values to them before you can pass them into the

new ListPrice(theType, theWeight)

constructor.

ok I reordered the main, so they are declared first

package org.mailprice.postage;

import java.util.Scanner;

public class Mail 
{
	
	// Main Method 
	public static void main(String[] args) 
	{
		
		//create Scanner to obtain input
		Scanner input = new Scanner(System.in);
		
	
		
		//prompt to read in type
		System.out.println("Please enter Letter or Envelope:");
		String theType = input.nextLine();
		
		
		/*myType.setType(theType);
		System.out.println();*/
		
		//prompt to read in Weight
		System.out.println("Please enter weight:");
		float theWeight = input.nextFloat();
		
		//Create a LetterPrice object
		new LetterPrice(theType, theWeight);
	
		
		
	} 
}
	
	

[paul spriesterbach]

Scott Winterbourne wrote:If you are going to pass the values into the constructor like you are trying on line 16, you would need to move line 16 below line 28 so both variables have been declared and initialized with the values from the user input.

You are also calling set methods for these values on line 31 which is redundant. You don't need to pass the values in the custructor as well as call the set methods. Here you can do one or the other to get the values into the LetterPrice Object.

Either you can move line 16 to line 29 and get rid of lines 31 and 32 OR on line 16 you can just call the default constructor passing no parameters "new LetterPrice()" and then use the set methods on lines 31 and 32.

how does what I did one post up look now?

[Scott Winterbourne]

You will want to save a reference to the new LetterPrice object in a reference variable so you can continue to use the object.

on line 30 you can use

LetterPrice myLetterPrice = new LetterPrice(theType, theWeight);

like you had before. This way you can call myLetterPrice.getType() or myLetterPrice.getWeight() to check that the object was created and the type and weight values have actually been set in it. Stick these method calls inside of a "System.out.println();" to print the values to the consol for varification.

You can then add more methods to the LetterPrice class and call them using the dot (.) oporator as well.

[paul spriesterbach]

Scott Winterbourne wrote:You will want to save a reference to the new LetterPrice object in a reference variable so you can continue to use the object.

on line 30 you can use

LetterPrice myLetterPrice = new LetterPrice(theType, theWeight);

like you had before. This way you can call myLetterPrice.getType() or myLetterPrice.getWeight() to check that the object was created and the type and weight values have actually been set in it. Stick these method calls inside of a "System.out.println();" to print the values to the consol for varification.

You can then add more methods to the LetterPrice class and call them using the dot (.) oporator as well.

cool, yea i added the myLetterPrice back in. Thank you, Im starting to understand it a bit. Im going to try to add the method into my LetterPrice class and post back here my completed work or if I get stuck. Thanks!

[Scott Winterbourne]

Great, I'm glad I could help. I look forward to seeing the completed work.

[paul spriesterbach]

Scott Winterbourne wrote:Great, I'm glad I could help. I look forward to seeing the completed work.

Awesome it works great, I still need to format it in the way my teacher wants it thats all. I enter in if its a envelope or a letter and the weight and it spits out the postage cost. What are the different ways I could make this code more efficient?

package org.mailprice.postage;

import java.util.Scanner;

public class Mail 
{
	
	// Main Method 
	public static void main(String[] args) 
	{
		
		//create Scanner to obtain input
		Scanner input = new Scanner(System.in);
		
		//prompt to read in type
		System.out.println("Please enter Letter or Envelope:");
		String theType = input.nextLine();
			
		/*myType.setType(theType);
		System.out.println();*/
		
		//prompt to read in Weight
		System.out.println("Please enter weight:");
		float theWeight = input.nextFloat();
		
		//Create a LetterPrice object
		Price myPrice = new Price(theType, theWeight);
		myPrice.calculatePrice();
	} 
}

package org.mailprice.postage;

//import java.util.*;
//import java.io.*;

public class Price 
{

//constructor
	public Price(String theType, float theWeight )
	{
		this.weight = theWeight;
		this.type = theType;
	}
	
//Method to Calculate the Price
public void calculatePrice()
	{
	System.out.println("***Weight is:" + weight);
	System.out.println("***Type is:" + type);
	
//Read the first letter of type
	firstLetter = type.toLowerCase().charAt(0);
	
//Calculate the Price	

	//Give Price for letters with weight 0 to 13 ounces
	if (firstLetter == 'l')
	{
	 if (weight < 1 )
	 {
		 System.out.println("First class postage is $0.49");
	 }
	  else if (weight <= 2)
	  {
		  System.out.println("First class postage is $0.70");
	  }
	   else if (weight <= 3)
	   {
	       System.out.println("First class postage is $0.91");
	   }
	    else if (weight <= 3.5)
	    {
		    System.out.println("First class postage is $1.12");
	    }
	     else if (weight <= 4)
	     {
		     System.out.println("First class postage is $1.61");
	     }
	      else if (weight <= 5)
	      {
	  		System.out.println("First class postage is $1.82"); 
	      }
	       else if (weight <= 6)
	       {
	   		System.out.println("First class postage is $2.03");
	       }
	        else if (weight <= 7)
	        {
	    		System.out.println("First class postage is $2.24");
	        }
	         else if (weight <=8)
	         {
	     		System.out.println("First class postage is $2.45");
	         }
	          else if (weight <=9)
	          {
	     		 System.out.println("First class postage is $2.66");
	          }
	           else if (weight <=10)
	           {
	       		System.out.println("First class postage is $2.87");
	           }
	            else if (weight <=11)
	            {
	        		System.out.println("First class postage is $3.08");
	    
	            }
	             else if (weight <= 12)
	             {
	         		System.out.println("First class postage is $3.29");
	         	 }
	              else if (weight <=13)
	              {
	          		System.out.println("First class postage is $3.50");
	              }
	              else 
	              {
	            	  return;
	              }
		}
	 	
		//calculate price of envelopes from 0 to 13 ounces
		if (firstLetter == 'e')
		{
			if (weight < 1 )
			 {
				 System.out.println("First class postage is $0.98");
			 }
			  else if (weight <= 2)
			  {
				  System.out.println("First class postage is $1.19");
			  }
			   else if (weight <= 3)
			   {
			       System.out.println("First class postage is $1.40");
			   }
			     else if (weight <= 4)
			     {
				     System.out.println("First class postage is $1.61");
			     }
			      else if (weight <= 5)
			      {
			  		System.out.println("First class postage is $1.82"); 
			      }
			       else if (weight <= 6)
			       {
			   		System.out.println("First class postage is $2.03");
			       }
			        else if (weight <= 7)
			        {
			    		System.out.println("First class postage is $2.24");
			        }
			         else if (weight <=8)
			         {
			     		System.out.println("First class postage is $2.45");
			         }
			          else if (weight <=9)
			          {
			     		 System.out.println("First class postage is $2.66");
			          }
			           else if (weight <=10)
			           {
			       		System.out.println("First class postage is $2.87");
			           }
			            else if (weight <=11)
			            {
			        		System.out.println("First class postage is $3.08");
			    
			            }
			             else if (weight <= 12)
			             {
			         		System.out.println("First class postage is $3.29");
			         	 }
			              else if (weight <=13)
			              {
			          		System.out.println("First class postage is $3.50");
			              }
			              else 
			              {
			            	  return;
			              }
		}
		
	} 	
	
//getter for Weight
	public float getWeight() 
	{
		return this.weight;
	}
//setter for Weight
	public void setWeight(float weight) 
	{
		this.weight = weight;
	}
//getter for Type
	public String getType() 
	{
		return this.type;
	}
//setter for Type
	public void setType(String type) 
	{
		this.type = type;
	}
//Initialize	
	private float weight;
	private String type;
	char firstLetter;
}