JavaScript如何获取数组最大值和最小值

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" /> 
<title>JavaScript获取数组最大值和最小值</title> 
<script type="text/javascript"> 
  //获取数组最大值 
  function findMax() 
  { 
    var arr = [3,4,76,2,54,23,78,90,89,99,234,12,23,76,89,90]; 
    var max = Array.max(arr); 
    document.getElementById("max").value = max; 
  } 
   
  //获取数组最大值函数 
  Array.max = function(arr) 
  { 
    return Math.max.apply(Math,arr);   
  } 
   
  //获取数组最小值 
  function findMin() 
  { 
    var arr = [34,4,3,67,89,30,23]; 
    var min = Array.min(arr); 
    document.getElementById("min").value = min;  
  } 
   
  //获取数组最小值函数 
  Array.min = function(arr) 
  { 
    return Math.min.apply(Math,arr);   
  } 
   
  window.onload = function(){ 
    findMax(); 
    findMin(); 
  }; 
</script> 
</head> 
 
<body> 
  <label>数组最大值：</label> 
  <input type="text" id="max"/> 
  <label>数组最小值：</label> 
  <input type="text" id="min"/> 
</body> 
</html>