<script type="text/javascript">
var arr = [14, 14, 53, 14, 14, 53, 67, 67];
var max = arr[0],min = arr[0];
var maxIndex = [];
maxIndex[0] = 0;
var minIndex = [];
minIndex[0] = 0;
var j = 1, k = 1;
for(var i = 1; i < arr.length; i ++){
if(max < arr[i]){
max = arr[i];
maxIndex[0] = i; 
}
if(min > arr[i]){
min = arr[i];
minIndex[0] = i;
}
}
for(var i = 0; i < arr.length; i ++){
if(max == arr[i]){
maxIndex[j] = i;
j ++;
}
if(min == arr[i]){
minIndex[k] = i;
k ++;
}
}
document.write("最大值为：" + max + "<br />");
document.write("最小值为：" + min + "<br />");
for(var i = 1; i < minIndex.length; i ++){
document.write("最小值的下标为：" + minIndex[i] + "<br />"); 
}
for(var i = 1; i < maxIndex.length; i ++){
document.write("最大值的下标为：" + maxIndex[i] + "<br />");
}
</script>

var a=[1,2,3,5];
alert(Math.max.apply(null, a));//最大值
alert(Math.min.apply(null, a));//最小值 

var a=[1,2,3,[5,6],[1,4,8]];
var ta=a.join(",").split(",");//转化为一维数组
alert(Math.max.apply(null,ta));//最大值
alert(Math.min.apply(null,ta));//最小值