Resolved: How to print matrix?

public override string ToString() {<br />
    string matrixView = "";</p>
<p>    for (int r=0; r<=this.rows; r++) {
        for (int c=0; c<=this.columns; c++) {
                
        }
    }

    return matrixView;
}
[/code]

</p>



Note:<br>
##################################<br>
<code>this.rows</code> = row number<br>
<code>this.columns</code> = column number<br>
<code>this.matrix</code>= 2-dimensional array used as data store<br>
##################################<br> 



In this code, I aim to make seem for example 4x4 matrix like:<br> 



<code>[0 0 0 0]</code><br>
<code>[0 0 0 0]</code><br>
<code>[0 0 0 0]</code><br>
<code>[0 0 0 0]</code><br> 



Each newline must be started with "[". Values(<code>this.columns</code> times) and spaces(<code>this.columns</code>-1 times) must be printed. Finally, the line must be ended with "]\n"
And these operations above must be done <code>this.rows</code>times.<br> 



I think in this way. But nested loops always make me confuse. So, I tried several times but I couldn't be successful at it. And <code>String.Concat</code> threw <code>NullReferenceException</code>when I tried  to concaten <code>matrixView</code> with "[", "]\n" and <code>this.matrix[r, c].ToString()</code>.<br> 



<h2 class="wp-block-heading">Answer:</h2>



I think you are looking for something like this:<br> 


<p>[code]public override string ToString() {<br />
    // When building string, better use StringBuilder instead of String<br />
    StringBuilder matrixView = new StringBuilder();</p>
<p>    // Note r < matrix.GetLength(0), matrix is zero based [0..this.rows - 1]
    // When printing array, let's query this array - GetLength(0)
    for (int r = 0; r < matrix.GetLength(0); r++) {
        // Starting new row we should add row delimiter 
        if (r > 0)<br />
            matrixView.AppendLine();</p>
<p>        // New line starts from [<br />
        matrixView.Append("["); </p>
<p>        // Note r < matrix.GetLength(1), matrix is zero based [0..this.rows - 1]
        for (int c = 0; c < matrix.GetLength(1); c++) {
            // Starting new column we should add column delimiter 
            if (c > 0)<br />
                matrixView.Append(' ');</p>
<p>            matrixView.Append(matrix[r, c]);<br />
        }</p>
<p>        // New line ends with [<br />
        matrixView.Append("]");<br />
    }</p>
<p>    return matrixView.ToString();<br />
}