text: var util = require("util");
  
  function Base() {
  	this.name = "base";
  	this.base = 1991;
  	this.sayHello = function() {
  		console.log("Hello " + this.name);
  	}
  
  	Base.prototype.showName = function() {
  		console.log(this.name);
  	}
  }
  
  //util 的方法:
  //isArray
  //isBoolean
  //isNull
  //isNullOrUndefined
  //isNumber
  //isString
  //isSymbol
  //isUndefined
  //isRegExp
  //isObject
  //isDate
  //isError
  //isFunction
  //isPrimitive
  //isBuffer