harwind

harwind

Java's for each loop

So, basically, I’m writing a method to check application numbers in my array ‘applications,’ and this method receives a parameter to verify that specific application number and compares it to the application numbers in the list.
So first look at the code:

public boolean hasApplicationNumber(int number) {
    if (number <= 3 ) {
        throw new IllegalArgumentException("bad number");   
    }

    for (ApplicationData current : applications) {
        if (number == current.getApplicationNumber() ) {    
            return true;
        }
    }
    return false;
}  

JUnit test to validate the application number:

public void shouldHaveApplicationNumber1() {
    University westGeorgia = new University("West Georgia");
    ApplicationData student1 = new ApplicationData(9, 7.0, 400);
    westGeorgia.addApplication(student1);
    assertEquals(true, westGeorgia.hasApplicationNumber(1));
}

This JUnit test is failing because my code returns “false” instead of “true.”

However, if I change the return values in my “hasApplicationNumber” method to true (at the very bottom of the method), this test will pass, but another test I have (that doesn’t allow the list to exceed 10) will return “true” when it is supposed to be “false,” causing that test to fail (I didn’t include that test because it is very similar to the one I have already provided — just “1” is changed to “10” and “true”
I’m beginning to suspect that either my test is being ignored by the Java compiler, or my for-each loop is executing correctly and returning “true,” but since I followed this documentation, I have that lingering false at the very end, which may be declaring the item false nonetheless.

I might be overthinking this, but I’m at a loss on how to change the for-each loop in the method I wrote. Any assistance in sorting this out would be much appreciated!

Most Liked

dtonhofer

dtonhofer

This JUnit test is failing because my code returns “false” instead of “true.”

Isn’t the JUnit test failing because the

hasApplicationNumber(1)

throws?

At this point, the easiest way to unconfuse yourself is to add a few print statements into the test code.

System.out.println("After test for throw );

etc.

finner

finner

hi @harwind -
According to the code you have pasted when you pass 1 into the method hasApplicationNumber an IllegalArgumentException will be thrown. So the test should fail.
I’ve also noticed that you are using double in the ApplicationData class but treating them as int in the hasApplicationNumber method.
Here is a stripped down version without the ApplicationData class and using int.

public class DevTalkTest {

    private final int[] numbers = new int[]{9, 7, 400};

    @Test
    public void shouldHaveApplicationNumber1() {
        assertTrue(hasApplicationNumber(1));
    }


    public boolean hasApplicationNumber(int number) {
        if (number <= 3) {
            throw new IllegalArgumentException("bad number");
        }
        for (int num : numbers) {
            if (num == number) return true;
        }
        return false;
    }


}

The tests will fail with the error:

bad number
java.lang.IllegalArgumentException: bad number
. . . 
finner

finner

I was going to suggest setting a breakpoint on the last line.

Where Next?

Popular General Dev topics Top

AstonJ
If you had the ear of a language creator, what would you say - what could they do to make a language that you would use? :upside_down_face:
New
DevotionGeo
As the title suggests, this thread will contain some real wisdom came from experience. Please add something meaningful than fancy looking...
New
New
jamiedumont
This is all going to be a bit hand-wavey and straight off the top of my head, so bear with me, but it’s a thought/debate that’s been ratt...
New
dwaynebradley
In their weekly newsletter, Jared Santo from the Changelog shared this blog post by Mark Ericksen over at fly.io: What is really inter...
New
AstonJ
Just listened to @rvirding’s interview here and he mentions #lua (and Luerl) - just wondered if anyone’s used Lua and what you think of it?
New
TwistingTwists
Hello Fellow developers, I have been trying to wrap my head around How difficult would it have been to be a dev 20-30 years ago? I have...
New
foxtrottwist
A few weeks ago I started using Warp a terminal written in rust. Though in it’s current state of development there are a few caveats (tab...
New
AstonJ
00:00 The Year 2022 00:38 Web3 03:28 Metaverse 05:05 AI 06:22 Databases 07:31 JavaScript 09:58 Other Trends to Know WDYT - what wi...
New
AstonJ
I’ve been watching Prag Dave’s Elixir course and I noticed he uses tree: Tree is a recursive directory listing program that produces a ...
New

Other popular topics Top

PragmaticBookshelf
Design and develop sophisticated 2D games that are as much fun to make as they are to play. From particle effects and pathfinding to soci...
New
AstonJ
There’s a whole world of custom keycaps out there that I didn’t know existed! Check out all of our Keycaps threads here: https://forum....
New
AstonJ
I’ve been hearing quite a lot of comments relating to the sound of a keyboard, with one of the most desirable of these called ‘thock’, he...
New
DevotionGeo
The V Programming Language Simple language for building maintainable programs V is already mentioned couple of times in the forum, but I...
New
mafinar
This is going to be a long an frequently posted thread. While talking to a friend of mine who has taken data structure and algorithm cou...
New
PragmaticBookshelf
Author Spotlight Jamis Buck @jamis This month, we have the pleasure of spotlighting author Jamis Buck, who has written Mazes for Prog...
New
Help
I am trying to crate a game for the Nintendo switch, I wanted to use Java as I am comfortable with that programming language. Can you use...
New
AstonJ
If you want a quick and easy way to block any website on your Mac using Little Snitch simply… File &gt; New Rule: And select Deny, O...
New
New
PragmaticBookshelf
Develop, deploy, and debug BEAM applications using BEAMOps: a new paradigm that focuses on scalability, fault tolerance, and owning each ...
New