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Thread: confused about this for loop/ array?

  1. #1
    Junior Member
    Join Date
    Mar 2014
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    Default confused about this for loop/ array?

    int [] [] mat = new int [3] [4]; 
    for (int row = 0;  row < mat.length; row ++ ) 
        for ( int col = 0; col < mat[0].length; col++ ) 
             if ( row < col ) 
                mat [row] [col] = 1; 
                else if (row == col ) 
                mat [row] [col] = 2;
                mat [row] [col] = 3; 

    I'm completely lost as how this work, could someone break it down into simple terms for me?

  2. #2
    Super Moderator Norm's Avatar
    Join Date
    May 2010
    Eastern Florida
    Thanked 2,465 Times in 2,416 Posts

    Default Re: confused about this for loop/ array?

    A 2D array requires two indexes to access an element in the array.
    The posted code uses the variable row to index into the first dim of the array
    and uses the variable col to index into the second dim of the array.
    mat[row][col] represents one element in the array.

    To see what is in the array, use the Arrays class's deepToString() method:
    System.out.println("an ID "+ java.util.Arrays.deepToString(theArrayName));
    If you don't understand my answer, don't ignore it, ask a question.

  3. The Following User Says Thank You to Norm For This Useful Post:

    GregBrannon (April 18th, 2014)

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