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Issue 237 fixed: 3.5 listing #241

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Merged
pearcej merged 2 commits into from
Jul 27, 2026
Merged

Issue 237 fixed: 3.5 listing #241

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99b99c0
add listing
habibasorour Jul 27, 2026
7e5e090
added listing in text
habibasorour Jul 27, 2026
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9 changes: 5 additions & 4 deletions source/ch3_javadatatypes.ptx
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Original file line number Diff line number Diff line change
Expand Up @@ -777,11 +777,11 @@ public class Histo {
<title>Arrays</title>

<p>
As was said at the outset of this section, we are going to use Java <c>ArrayLists</c> because they are easier to use and more closely match the way that Python lists behave. However, if you look at Java code on the internet or even in your core Java books you are going to see examples of something called an array. In fact, you have already seen one example of an array declared in the &#x2018;Hello World&#x2019; program. Let's rewrite this program to use primitive arrays rather than array lists.
As was said at the outset of this section, we are going to use Java <c>ArrayLists</c> because they are easier to use and more closely match the way that Python lists behave. However, if you look at Java code on the internet or even in your core Java books you are going to see examples of something called an array. In fact, you have already seen one example of an array declared in the &#x2018;Hello World&#x2019; program. <xref ref="java-array" text="type-global"/> is a rewritten version of <xref ref="java-histogram" text="type-global"/> that uses primitive arrays rather than array lists.
</p>


<program xml:id="java-array" interactive="activecode" language="java" datafile="test.dat">
<listing xml:id="java-array">
<program interactive="activecode" language="java" datafile="test.dat">
<code>
import java.util.Scanner;
import java.io.File;
Expand Down Expand Up @@ -812,9 +812,10 @@ public class HistoArray {
}
</code> <tests> </tests>
</program>
</listing>

<p>
The main difference between this example and the previous example is that we declare <c>count</c> to be an <c>Array</c> of integers. We also can initialize short arrays directly using the syntax shown here: <c>Integer[] count = {0,0,0,0,0,0,0,0,0,0}</c>Then notice that we can use the square bracket notation <c>count[idx]</c> to index into an array.
The main difference between <xref ref="java-array" text="type-global"/> and <xref ref="java-histogram" text="type-global"/> is that we declare <c>count</c> to be an <c>Array</c> of integers. We also can initialize short arrays directly using the syntax shown here: <c>Integer[] count = {0,0,0,0,0,0,0,0,0,0}</c>Then notice that we can use the square bracket notation <c>count[idx]</c> to index into an array.
</p>
</section>

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