JavaScript数组some()方法详解与兼容性处理

语法与参数说明

array.some(callback[, thisObject]);

if (!Array.prototype.some)
{
 Array.prototype.some = function(fun /*, thisp*/)
 {
  var len = this.length;
  if (typeof fun != "function")
   throw new TypeError();

  var thisp = arguments[1];
  for (var i = 0; i < len; i++)
  {
   if (i in this &&
     fun.call(thisp, this[i], i, this))
    return true;
  }

  return false;
 };
}

<html>
<head>
<title>JavaScript Array some Method</title>
</head>
<body>
<script type="text/javascript">
if (!Array.prototype.some)
{
 Array.prototype.some = function(fun /*, thisp*/)
 {
  var len = this.length;
  if (typeof fun != "function")
   throw new TypeError();

  var thisp = arguments[1];
  for (var i = 0; i < len; i++)
  {
   if (i in this &&
     fun.call(thisp, this[i], i, this))
    return true;
  }

  return false;
 };
}

function isBigEnough(element, index, array) {
 return (element >= 10);
}

var retval = [2, 5, 8, 1, 4].some(isBigEnough);
document.write("Returned value is : " + retval );

var retval = [12, 5, 8, 1, 4].some(isBigEnough);
document.write("<br />Returned value is : " + retval );
</script>
</body>
</html>

Returned value is : false
Returned value is : true