CODEWITHSUNDEEP
javaparametersconstructorarguments
Omar Kadery
Omar Kadery

Reputation: 193

Arguments won't get passed into object

public class BottledWaterTester {
public static void main (String args[])
{
    BottledWaterCalculator tester = new BottledWaterCalculator("USA", 350000000, 190.0, 8.5, 12.0);


    System.out.println("The country is " + tester.getCountryName());
    System.out.println("The population is " + tester.getPopulation());
    System.out.println("The number of times the bottles circle the Equator is " + tester.getNumberCircled());
    System.out.println("The average length of a bottle is " + tester.getLength());
    System.out.println("The average volume of a bottle is " + tester.getVolume());
}

}

So I have this code above. But when I run it I get this output:

*run:

The country is null

The population is 0

The number of times the bottles circle the Equator is 0.0

The average length of a bottle is 0.0

The average volume of a bottle is 0.0

BUILD SUCCESSFUL (total time: 0 seconds)*

WHY?? I'm clearly passing values into my tester object. The constructor is defined here:

public class BottledWaterCalculator {

//instance vars
private String countryName;
private int population;
private double numberCircled;
private double avgLength;
private double avgVolume;

//constructor
// note: constructor name must always be same as public class name, or else it's a method
public BottledWaterCalculator(String country, int pop, double number, double lengthAvg, double volumeAvg)
{
    country = countryName;
    pop = population;
    number = numberCircled;
    lengthAvg = avgLength;
    volumeAvg = avgVolume;
}

I'm really new to programming so I don't understand what's going on.

Upvotes: 1

Views: 114

Answers (4)

THA
THA

Reputation: 1

you need to assign this keyword while assign to constructor.

Upvotes: 0

Raghavendra Reddy Busireddy
Raghavendra Reddy Busireddy

Reputation: 485

Change the code as below:

public class BottledWaterCalculator {

//instance vars
private String countryName;
private int population;
private double numberCircled;
private double avgLength;
private double avgVolume;

//constructor
// note: constructor name must always be same as public class name, or else it's a method
public BottledWaterCalculator(String country, int pop, double number, double lengthAvg, double volumeAvg)
{
    countryName = country;
    population = pop;
    numberCircled = number ;
    avgLength = lengthAvg ;
    avgVolume = volumeAvg ;
}

Upvotes: 0

Welsh
Welsh

Reputation: 5468

In your constructor flip variable assignment. Ex:

countryName = country;

Your currently setting what you are passing in to the local variable value. (Which are all empty / null / unassigned)

Upvotes: 0

Maxim Efimov
Maxim Efimov

Reputation: 2737

public BottledWaterCalculator(String country, int pop, double number, double lengthAvg, double volumeAvg)
{
  countryName  = country ;
  population=  pop;
  numberCircled =  number ;
  avgLength = lengthAvg;
  avgVolume = volumeAvg ;
}

wrong order of variables, you are assigning values to constructor parameters, not objects one

Upvotes: 1

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