javascript definition guide(javascript權威指南)第六章 Example 6-2裡一個小錯誤

javascript definition guide(javascript權威指南)第六章 Example 6-2裡的例子有一個小錯誤

/*** Copy the enumerable properties of p to o, and return o.* If o and p have a property by the same name, o's property is overwritten.* This funcdtion does not handle getters and setters or copy attributes.*/function extend(o, p){for (prop in p)o[prop] = p[prop];return o}/*** Return a new object that holds the properties of both o and p.* If o and p have properties by the same name, the values from o are used*/function union(o, p) {return extend(extend({}, o), p);}

這裡的union函數實現，如果o和p有相同的屬性，o的屬性還是會被p中的屬性覆蓋。

正確的函數應該是：

function union(o, p) {return extend(p, extend({}, o));}