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POhow to find average of a List java
 

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  1. POhow to find average of a List java
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    <p>I have a question on how to find the average of a List. I don't know what is wrong with my code, because I did the same for all the three averages but only the first one works, the others just show <code>0</code>, as shown below in my output:</p> <pre><code>Average: 58 0 0 </code></pre> <p>Below is my code:</p> <pre><code>import java.io.File; import java.io.FileNotFoundException; import java.io.FileReader; import java.util.Scanner; import java.io.IOException; import java.util.ArrayList; import java.util.List; public class Hurricanes2{ public static void main(String args[]) throws FileNotFoundException{ Scanner scan = new Scanner(new FileReader(new File("/Users/timothylee/hurcdata2.txt"))); List&lt;Integer&gt; year = new ArrayList&lt;Integer&gt;(); List&lt;Integer&gt; windspeed = new ArrayList&lt;Integer&gt;(); List&lt;Integer&gt; pressure = new ArrayList&lt;Integer&gt;(); List&lt;String&gt; name = new ArrayList&lt;String&gt;(); List&lt;Integer&gt; category = new ArrayList&lt;Integer&gt;(); while(scan.hasNext()){ String input = scan.nextLine(); String[] hurricane = input.split("\\s+"); year.add(Integer.parseInt(hurricane[0])); windspeed.add(Integer.parseInt(hurricane[2])); pressure.add(Integer.parseInt(hurricane[3])); name.add(hurricane[4].trim()); category.add(Integer.parseInt(hurricane[5])); } int sum = 0; for(Integer integer : pressure){ sum += integer.intValue(); } double average = sum / pressure.size(); // create menu System.out.printf("%50s%n%n", "Hurricanes 1980 - 2006"); System.out.printf("%1s%20s%20s%20s%20s%n", "Year", "Hurricane", "Category", "Pressure(mb)", "Wind Speed (mph)"); System.out.println("__________________________________________________" + "__________________________________"); for(int i = 0; i &lt; year.size(); i++){ System.out.printf("%4d%20s%20d%20d%20d%n", year.get(i), name.get(i) , category.get(i), pressure.get(i), windspeed.get(i)); } System.out.println("__________________________________________________" + "__________________________________"); int averageCategory = 0; int averagePressure = 0; int averageWindSpeed = 0; for(int i = 0; i &lt; category.size(); i++){ averageCategory = i / category.get(i); averagePressure = i / pressure.get(i); averageWindSpeed = i / windspeed.get(i); } System.out.printf("%1s%35d%35d%35d%n", "Average: ", averageCategory, averagePressure, averageWindSpeed); } } </code></pre> <p>How can I fix this? Any help will be greatly appreciated.</p>
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    1. USuser2967353
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    1. COPost the input file.
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    2. COParallel lists is total madness, dude: use OBJECTS for stuff like this. Would have properties for each item: name, year, windspeed, pressure, category. Then just loop over the objects and compute the averages.
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      1. USRob
 

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