CODEWITHSUNDEEP
java
user3199687
user3199687

Reputation: 3

Java calling methods

I have two classes in separate files and I'm trying to import one class from the other. I was wondering how I could go about doing that? The the test class is supposed to take both methods from the first class and display them. I was wondering how I would go about doing that?

The first class:

public class StringUtils {
    public static String padLeft(String orig, int n) {
        orig = "testing for lab06";
        return String.format("%1$-" + n + "orig", orig);
    }

    public static String padLeft(String orig, int n, char c) {
        return String.format("%1$-" + n + c + "orig", orig);
    }
}

The second (or test) class

public class StringUtilsTest {
    public static void main(String args[]) {
        System.out.println(padLeft);
        System.out.println(padLeft);
    }
}

Upvotes: 0

Views: 102

Answers (2)

Nick Holt
Nick Holt

Reputation: 34301

Assuming both classes are in the same package (it looks like they're in the default package from the code in the question) you've got a couple of options.

The first option is to explicitly refer to the class containing the padLeft method like this:

public class StringUtilsTest
{
  public static void main(String args[])
  {
    System.out.println(StringUtils.padLeft("test 1", 5));
    System.out.println(StringUtils.padLeft("test 2", 5));
  }
}

Had StringUtils and StringUtilsTest been in different packages (not that usual for a class and its test) you would have needed to import StringUtils into StringUtilsTest with a normal import.

The second option is to use a import static like this:

import static StringUtils.padLeft;

public class StringUtilsTest
{
  public static void main(String args[])
  {
    System.out.println(padLeft("test 1", 5));
    System.out.println(padLeft("test 2", 5));
  }
}

Upvotes: 1

JoaoFilipeClementeMartins
JoaoFilipeClementeMartins

Reputation: 1820

In java the main method is the one that is going to run the rest of the code. So what u need to do is inside the main create an object of type StringUtils:

public class StringUtilsTest{

public static void main(String[] args){
    StringUtils str = new StringUtils();
    System.out.println(str.padLeft("random string",5));
    System.out.println(str.padLeft("random string",5,"c"));
}

that str object now can hold the calls to the methods inside StringUtils class. For the methods to work properly you need to pass the arguments inside them like i did.

Note: Like this you are using the default constructor for java classes if you want to define the constructor you have to do in the class StringUtils the following:

public class StringUtils{
    public StringUtils(){
        //and in here set the behavior you wish it to have.
    }
}

Hope it helps

Upvotes: 0

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