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POParsing data from text file into multiple arrays in Java
 

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  1. POParsing data from text file into multiple arrays in Java
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    <p>Let me start by saying I am fairly new to Java so forgive me if I am making obvious mistakes...</p> <p>I have a text file that I must read data from and split the data into separate arrays.</p> <p>The text file contains data in this format (although if necessary it can be slightly modified to have identifier tags if it is the only way)</p> <p>noOfStudents<br> studentNAme studentID numberOfCourses<br> courseName courseNumber creditHours grade<br> courseName courseNumber creditHours grade<br> courseName courseNumber creditHours grade<br> .<br> .<br> studentNAme studentID numberOfCourses<br> courseName courseNumber creditHours grade<br> courseName courseNumber creditHours grade<br> courseName courseNumber creditHours grade<br> .<br> . </p> <p>The first line indicates the total number of "students" that will be listed and will need to be moved to arrays. One array will contain student information so<br> studentName, studentID, numberOfCourses<br> to one array, and<br> courseName, courseNumber, creditHours, grade<br> to the second array.</p> <p>My problem is stemming from how to parse this data.<br> I'm currently reading in the first line, converting to int and using that to determine the size of my student array. After that I am at a loss for how to move the data into arrays and have my program know which array to move which lines into. </p> <p>One thing to note is that the number of courses each student takes is variable so I can't simply read 1 line into one array, then 3 lines into the next, etc. </p> <p>Will I need to use identifiers or am I missing something obvious? I've been looking at this problem for a week now and at this point I'm just getting frustrated.</p> <p>Any help is greatly appreciated! thank you</p> <p>edit: Here is the code section I am working on at the moment. </p> <pre><code>public static void main(String args[]) { try{ // Open the file FileInputStream fstream = new FileInputStream("a1.txt"); // Get the object of DataInputStream DataInputStream in = new DataInputStream(fstream); BufferedReader br = new BufferedReader(new InputStreamReader(in)); String strLine; // temporarily holds the characters from the current line being read String firstLine; // String to hold first line which is number of students total in file. // Read firstLine, remove the , character, and convert the string to int value. firstLine = br.readLine(); firstLine = firstLine.replaceAll(", ", ""); int regStudnt = Integer.parseInt(firstLine); // Just to test that number is being read correctly. System.out.println(regStudnt + " Number of students\n"); // 2D array to hold student information String[][] students; // Array is initialized large enough to hold every student with 3 entries per student. // Entries will be studentName, studentID, numberOfCourses students = new String[3][regStudnt]; //Read File Line By Line while ((strLine = br.readLine()) != null) { // Split each line into separate array entries via .split at indicator character. // temporary Array for this is named strArr and is rewriten over after every line read. String[] strArr; strArr = strLine.split(", "); } //Close the input stream in.close(); }catch (Exception e){//Catch exception if any System.err.println("Error: " + e.getMessage()); } } </code></pre> <p>I hope this helps someone lead me in the right direction.</p> <p>I guess the major problem I'm having from this point is finding out how to loop in such a way that the student info is read to the student array, then the course info to the appropriate course array location, then start again with a new student until all students have been read.</p>
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    1. COIs this homework or why do you want/need to use arrays? If so, please tag appropriately.
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      1. USPhilipp Reichart
    2. CO@PhilippReichart: it is obviously homework, but that's a moot point. To the original poster, will there be an empty line between each student's data? Can you post a sample of the data file?
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    3. COFor starters, you might want to read in each line, split it on spaces using `line.split("\\s")` and then decide how to continue based on the number of elements you received from that split.
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