本文实例讲述了JavaScript通过prototype给对象定义属性的用法。分享给大家供大家参考。具体分析如下：

下面的JS代码定义了movie对象。在使用对象的过程中又通过prototype给对象添加了isComedy属性，调用的时候直接使用object.isComedy即可，非常方便。

<script type="text/javascript"><!--function movieToString() { return("title: "+this.title+" director: "+this.director);}function movie(title, director) { this.title = title; this.director = director || "unknown"; //if null assign to "unknown" this.toString = movieToString; //assign function to this method pointer}var officeSpace = new movie("OfficeSpace");var narnia = new movie("Narnia","Andrew Adamson");movie.prototype.isComedy = false; //add a field to the movie's prototypedocument.write(narnia.toString());document.write("<br />Narnia a comedy? "+narnia.isComedy);officeSpace.isComedy = true; //override the default just for this objectdocument.write("<br />Office Space a comedy? "+officeSpace.isComedy);//--></script>

希望本文所述对大家的javascript程序设计有所帮助。