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Thread: Sum from a file

  1. #1
    Junior Member
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    Default Sum from a file

    Hi guys,

    below I make one program to read in one column the strings and the second column the int:
    import java.io.File;
    import java.util.Scanner;
     
     
    public class Main {
     
    	private Scanner x;
     
    		public void openFile(){
    			try{
    				x=new Scanner(new File("myfile.txt"));
    			}
    			catch (Exception e){
    					System.out.println("Could not find file");
    								}
    		}
    public void readFile(){
     
    int loop=0;
    			do{
     
    			x.hasNext();
    			String a= x.next();
    			int b=x.nextInt();
     
    			System.out.printf("%s %s\n",a,b);
    			loop++;			
    			}while (loop<10);}
     
    public void closeFile(){
    	x.close();
    }
    }

    The file includes 10 lines and 2 columns and is like this:

    abc 12
    def 234
    rrt 333

    ..
    ..
    ..

    Now what I need is to sum all int of the 2 column. So I try to make some small changes to :
    import java.io.File;
    import java.util.Scanner;
     
     
    public class ReversePartA {
     
        private Scanner x;
     
            public void openFile(){
                try{
                    x=new Scanner(new File("myfile.txt"));
                }
                catch (Exception e){
                        System.out.println("Could not find file");
                                    }
            }
    public void readFile(){
    int j=0;
    int sum=0;
    int loop=0;
                for(j=0; j<=10; j++){
     
                x.hasNext();
                String a= x.next();
                int b=x.nextInt();
                sum +=b;
     
     
                }System.out.println(sum);}
     
     
     
    public void closeFile(){
        x.close();
    }
    }

    the results of sum from this program is crazy. Any ideas?


  2. #2
    Super Moderator
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    Default Re: Sum from a file

    Read the whole line as a String, and then parse the String into two parts using the split() method. Please don't store the results in parallel arrays. Create a class instead.

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