js判断数据类型一个小实例

<script>
 /**
  * 检测javascript 基本数据类型和内置对象
  * 参数：O表示检测的值
  * 返回值："undefined","number","boolean","string","function","regexp","array","date","error","object","null"
  */
  funtion typeOf(O){
var _toString = Object.prototype.toString;
// 获取对象的toString()方法引用
// 列举基本数据类型和内置对象类型，可以进一步补充该数组的检测数据类型范围
var _type = {
"undefined" : "undefined",
"number" : "number",
"boolean" : "boolean",
"string" : "string",
"[object Function]" : "function",
"[object RegExp]" : "regexp",
"[object Array]" : "array",
"[object Date]" : "date",
"[object Error]" : "error",
}
return _type[typeof O] || _type[_toString.call(O)] || (O ? "object" : "null");
  }
</script>