Using method on a program

[Alfonso Saballett]

Hi All

We are suppose to create methods and then develop a program that demonstrates each method.

Here is the Class that I developed, after I show you the Class I will post the program.

   

import java.util.Scanner;

public class Person_test
{
	private String name;
	private int age;
	
	public void readInput()
	{
	//	Scanner keyboard = new Scanner(System.in);
	//	System.out.println("What is the name of the person?");
	//	name = keyboard.nextLine();
		
	//	System.out.println("How old is " + name + "?");
	//	age = keyboard.nextInt();
		
	}
	
	public void writeOutput()
	{
		System.out.println("Name = " + name);
		System.out.println("Age = " + age);
	}
	
	public void setName(String newName)
	{
		name = newName;
		
		Scanner keyboard = new Scanner(System.in);
		System.out.println("What is the name of the person?");
		name = keyboard.nextLine();
		
	}
	
	public void setAge(int newAge)
	{
		Scanner keyboard = new Scanner(System.in);
		System.out.println("How old is " + name + "?");
		age = keyboard.nextInt();
			
			if (newAge >= 0)
				age = newAge;
			else
		{
			System.out.println("ERROR: Age is negative");
			System.exit(0);
		}
	}
	
	public void setPerson(String newName, int newAge)
	{
		setName(newName);
		setAge(newAge);
	}
	public String getName()
	{
		return name;
	}
	public int getAge()
	{
		return age;
	}
	public boolean equals(Person newPerson)
	{
		return (name.equalsIgnoreCase(newPerson.name))&&
				(age == newPerson.age)&&
				(age > newPerson.age) &&
				(age < newPerson.age);

	}
	
}

 

OK now for the program I developed to use the methods:

 import java.util.Scanner;

public class driverTest_AS_test
{
	public static void main (String[] args) 
	{
		String driversName;
		int driversAge;
		
		Person driverID = new Person();
		
		driverID.setName(driversName);
		driverID.setAge(driversAge);
	}

}   

So when I do this I get the error: variable driversName might not have been initialized and same for the driversAge. Can someone help please.

[anu kuntala]

You have declared drivresName and driversAge as Local variables. You cannot use localvariables without initializing them. Declare the variables outside the main method.Try with this code.

  
import java.util.Scanner;   
  
public class driverTest_AS_test   
{   
    String driversName;   
    int driversAge; 
    public static void main (String[] args)    
    {   
        Person driverID = new Person();   
           
        driverID.setName(driversName);   
        driverID.setAge(driversAge);   
    }   
  
}

  

[Alfonso Saballett]

I tried it and I got the following error:

"non-static variable driversName cannot be referenced from a static context" and the same with driversAge.

any ideas.

Thanks

[Sagar Rohankar]

OR, initialize them at the time of declaring !

  import java.util.Scanner;     
     
 public class driverTest_AS_test     
 {     
     
     public static void main (String[] args)      
     {     

         String driversName = "Alfonso";     
         int driversAge = 20;   
 
         Person driverID = new Person();     
              
         driverID.setName(driversName);     
         driverID.setAge(driversAge);     
     }     
     
 }  

[Sagar Rohankar]

Alfonso Saballett wrote:

"non-static variable driversName cannot be referenced from a static context" and the same with driversAge.

That's means, static method can see static varibale and methods only, so to access "driverName" and "driverAge", declare them static !!

[Harshit Rastogi]

Alfonso Saballett wrote:
So when I do this I get the error: variable driversName might not have been initialized and same for the driversAge. Can someone help please.

Then initialize them inside main.

 
public static void main(String args[]){
String driversname="";
int age=0;
}
   

the best way is to pass the drivername and age in the constructor.. So you need to create a parameterized constructor

[Alfonso Saballett]

Thanks guys.