still looking for additional help with this
well I'm at the end of my program of minesweeper that i built using java script so now one last thing to do is placing flags on the square that are bombs. By using the rightclick function I am getting the error of:
Error: 'document.getElementById(...)' is null or not an object
Here is the part of code that is getting it. Now my images are in a folder and the flag image is called sqt01. So i have changed the document.getElementbyId part couple of times pointing it to different images but just get that error.
//Global
//store the value of each square
var gaValue = new Array(8);
for (i = 0; i <= 8; i++) {
gaValue[i] = new Array(8);
}
for (i = 0; i <= 8; i++) {
//loop through each item in those row
for (j = 0; j <= 8; j++) {
gaValue[i][j] = 0;
}
}
//Store the status of each square
var gaSquare = new Array(8);
for (j = 0; j <= 8; j++) {
gaSquare[j] = new Array(8);
}
for (j = 0; j <= 8; j++) {
//loop through each item in those row
for (i = 0; i <= 8; i++) {
gaSquare[i][j] = 'c';
}
}
//Track of whether the game is over or not (starts this with false)
var gbGameOver = false;
function vInit()
{
var strHTML;
var i;
var j;
strHTML = "<table style='margin-left:auto;margin-right:auto'>";
strHTML += "<tr><td colspan='8' style='text-align:center'>MineSweeper</td></tr>";
strHTML += "<tr><td colspan='8' style='text-align:center'><input type='button' id='btnNew' value='New Game' onclick='vNewGame()'></td></tr>";
//Loop through the rows to build the table of tiles
for (i = 0; i < 8; i++)
{
strHTML += "<tr>";
for (j = 0; j < 8; j++)
strHTML += '<td><img src="images/sqt0.png" id="square' + i + ', ' + j + '" onclick="vClick(' + i + ', ' + j + ')" onmousedown="vRightClick(' + i + ', ' + j + ')"/></td>';
strHTML += "<tr>";
}
strHTML += '<tr><td colspan="8" style="text-align:center"><textarea id="taOut" cols="18" rows="10"></textarea></td></tr>';
strHTML += "</table>";
frmGrid.innerHTML = strHTML;
//Place bombs
var iBomb = 0;
var iRow = Math.floor(Math.random() * 8);
var iCol = Math.floor(Math.random() * 8);
while (iBomb < 8)
{
while (gaValue[iRow][iCol] == 9)
{
iRow = Math.floor(Math.random() * 8);
iCol = Math.floor(Math.random() * 8);
}
gaValue[iRow][iCol] = 9;
iBomb++;
}
//Calculate clue values around mines
var iMine = 0;
for (i = 0; i < 8; i++)
{
for (j = 0; j < 8; j++)
{
for (k = (i - 1) ; k <= (i + 1) ; k++)
for (m = (j - 1) ; m <= (j + 1) ; m++)
if (k >= 0 && k <= 7 && j >= 0 && j <= 7)
if (gaValue[k][m] == 9)
iMine++;
if (gaValue[i][j] != 9)
gaValue[i][j] = iMine;
iMine = 0;
}
}
}
//Get the ID of the image I need to change
function vClick(iRow, iCol)
{
var strID = "square" + iRow + ", " + iCol;
var strOut = "Gameover";
if (gbGameOver == false)
{
gaSquare[iRow][iCol] = 'o';
document.getElementById(strID).src = "images/" + gaValue[iRow][iCol] + ".png";
if (gaValue[iRow][iCol] == 9)
{
document.getElementById('taOut').value = strOut;
vOver();
}
if (gaValue[iRow][iCol] == 0)
{
vZero2(iRow, iCol);
}
}
}
//GameOver
function vOver()
{
var i;
var j;
var strID;
for (i = 0; i < 8; i++)
for (j = 0; j < 8; j++)
{
strID = "square" + i + ", " + j;
document.getElementById(strID).src = "images/" + gaValue[i][j] + ".png";
}
}
//Clearing area
function vZero2(iRow, iCol)
{
var i;
var j;
for (i = iRow - 1; i <= (iRow + 1) ; i++)
{
for (j = iCol - 1; j <= iCol + 1; j++)
{
if (i >= 0 && i < 8 && j >= 0 && j < 8)
if (gaSquare[i][j] != 'o')
vClick(i, j);
}
}
}
//Start new game
function vNewGame()
{
for (i = 0; i < 8; i++)
for (j = 0; j < 8; j++)
{
gaValue[i][j] = 0;
gaSquare[i][j] = 'c';
document.getElementById('square' + i + ', ' + j).src = 'images/sqt0.png';
}
gbGameOver = false;
vInit();
}
//no menu on right click
function bIsRightButtonClicked(e) {
var rightclick = false;
e = e || window.event;
if (e.which) {
rightclick = (e.which == 3);
} else if (e.button) {
rightclick = (e.button == 2);
}
return rightclick;
}
//Getting Flag when you right click
function vRightClick(iRow, iCol, e)
{
if (bIsRightButtonClicked(e))
{
gaSquare[iRow][iCol] = 'c';
gaSquare[iRow][iCol] = 'f';
document.getElementById('square' + i + ', ' + j).src = 'images/sqt1.png'; // Error: 'document.getElementById(...)' is null or not an object
vOver();
}
}
//Getting Flag when you right click
function vRightClick(iRow, iCol, e)
{
if (bIsRightButtonClicked(e))
{
gaSquare[iRow][iCol] = 'c';
gaSquare[iRow][iCol] = 'f';
document.getElementById('square' + i + ', ' + j).src = 'images/sqt1.png'; // Error: 'document.getElementById(...)' is null or not an object
vOver();
}
}
You cannot have whitespace or commas in your dom element ID attribute (See this post for more details and references). It must start with:
ID and NAME tokens must begin with a letter ([A-Za-z]) and may be followed by any number of letters, digits ([0-9]), hyphens ("-"), underscores ("_"), colons (":"), and periods (".")
With that I would replace your ', ' in your ID's with an '_'
Some examples of what your code needs to change to:
...
strHTML += '<td><img src="images/sqt0.png" id="square' + i + '_' + j +
'" onclick="vClick(' + i + ', ' + j +
')" onmousedown="vRightClick(' + i + ', ' + j + ')"/></td>';
...
document.getElementById('square' + i + '_' + j)
...
var strID = "square" + iRow + "_" + iCol;
...
Note, the onclick and onmousedown handlers/code generation remains the same