function preloadimages(arr){var newimages = [];var arr = (typeof arr != "object") ? [arr] : arr;  // 确保参数总是数组for(var i=0; i<arr.length; i++){newimages[i] = new Image();newimages[i].src = arr[i];}
}

preloadimages(['1.gif', '2.gif', '3.gif']).done(function(images){//当图片全部加载完成之后，执行此处的代码//images参数是Array类型，对应加载进来的图像//images[0]对应的是第一张图像
});

function preloadimages(arr){var newimages = [];var loadedimages = 0;var arr = (typeof arr != "object") ? [arr] : arr;function imageloadpost(){loadedimages++;if(loadedimages == arr.length){alert("图片已经加载完成");}}for(var i=0; i<arr.length; i++){newimages[i] = new Image();newimages[i].src = arr[i];newimages[i].onload = function(){imageloadpost();};newimages[i].onerror = function(){imageloadpost();};}
}

preloadimages(imagesarray, function(){// 图片加载完成之后执行的操作
});

preloadimages(imagesarray).done(function(){//图片加载完成后的操作
});

function preloadimages(arr){var newimages = [];var loadedimages = 0;var postaction = function(){};  // 此处增加了一个postaction函数var arr = (typeof arr != "object") ? [arr] : arr;function imageloadpost(){loadedimages++;if(loadedimages == arr.length){postaction(newimages);   // 加载完成用我们调用postaction函数并将newimages数组做为参数传递进去
        }}for (var i=0; i<arr.length; i++){newimages[i] = new Image();newimages[i].src = arr[i];newimages[i].onload = function(){imageloadpost();};newimages[i].onerror = function(){imageloadpost();};}return{ // 此处返回一个空白对象的done方法
        done: function(fun){postaction = fun || postaction;}}
}

preloadimages(['1.gif', '2.gif', '3.gif']).done(function(images){alert(images.length); //alerts 3
});