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PORecalling specific lines from an Array Java
 

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  1. PORecalling specific lines from an Array Java
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    <p>I'm trying to load a text file into an array, then work with the elements in the array.</p> <p>My text file is in the format:</p> <p>1 0 3 4 1</p> <p>1 0 3 4 2</p> <p>.....</p> <p>2 2 2 2 2 </p> <p>I cant figure out how to extract the different elements at specific indexes so that I can use them, or do math against them.</p> <pre><code> import java.io.BufferedWriter; import java.io.File; import java.io.FileWriter; import java.io.IOException; import java.io.PrintWriter; import java.util.ArrayList; import java.util.List; import java.util.Scanner; public class Coord { public int a,b,c,d,e,f; public static void main(String[] args) throws IOException { PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("/Users/evanlivingston/3a.txt", true))); Scanner sc = new Scanner(new File("/Users/evanlivingston/1.txt")); List&lt;Coord&gt; coords = new ArrayList&lt;Coord&gt;();{ // for each line in the file while(sc.hasNextLine()) { String[] numstrs = sc.nextLine().split("\\s+"); Coord c = new Coord(); c.a = Integer.parseInt(numstrs[1]); c.b = Integer.parseInt(numstrs[2]); c.c = Integer.parseInt(numstrs[3]); c.d = Integer.parseInt(numstrs[4]); c.e = Integer.parseInt(numstrs[5]); c.f = Integer.parseInt(numstrs[6]); coords.add(c); // now you have all coords in memory for( int i=0; i&lt;coords.size(); i++ ) { // j=i+1 to calculate the distance between two points only once, // not one way and back; also skip calculating distance between // the same point for( int j=i+1; j&lt;coords.size(); j++ ) { Coord c1 = coords.get(i); Coord c2 = coords.get(j); System.out.println(c2); } } } } } } </code></pre> <p>My main concern is performing an operation like subtracting c.f of index 3 from c.f of index 4. </p>
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    1. USevanlivingston
    1. USevanlivingston
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    1. COMaybe it's just a copy&paste error, but the closing `}` for the while loop should probably be after `coords.add(c);`.
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      1. USIshtar
 

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