Javascript 画布的问题

我正在用HTML5画布做一些测试。我正在尝试使用for循环在画布中绘制一组图像：

var blocks=["dirt","cactus","carvedSandstone","crackedStoneBrick","diamondOre","furnace","goldOre","grass","lapisOre","leaves","log1","sand","stone","stoneBrick","stoneMoss","woodOak"];
 for(var i;i<=blocks.length;i++){
  var id=document.getElementById(blocks[i]);
  var x=i*32;
  var y=0;
    if(x>=1000){
      y+=32;
   }
   ctx.drawImage(block,x,y);

如果我含糊不清，如果你有任何问题，请告诉我

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var id=document.getElementByIdblocks[i]；应该是var block=document.getElementByIdblocks[i]；，否？

您调用ctx.drawImageblock，x，y，但您从未设置任何名为block的变量，很可能id应该是blockOh，这一定是输入错误。但这并不能解决问题。也许初始化i:forvar i=0。。。

dirt=document.getElementById("dirt");
ctx.drawImage(dirt,0,0);