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POBinary Search Tree - search function return object (C++)
 

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  1. POBinary Search Tree - search function return object (C++)
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    <pre class="lang-cpp prettyprint-override"><code>//Node.cpp Node::Node(DataType Item):item(Item) { lchild = 0; rchild = 0; } DataType Node::getItem() { DataType anItem = item; return anItem; } void Node::setItem( const DataType &amp; data) { item = data; } Node* Node::getLChild() const { Node * p = lchild; return p; } void Node::setLChild(Node * p) { lchild = p; } Node* Node::getRChild() const { Node * p = rchild; return p; } void Node::setRChild(Node * p) { rchild = p; } Node::~Node() { } //BST.cpp DataType * BST::Search(const string name) { return Search(name, root); } DataType * BST::Search(const string name, Node * r) { if(r != 0) { if (name.compare(r-&gt;getItem().getname()) == 0) return &amp;(r-&gt;getItem()); else { if (name.compare(r-&gt;getItem().getname()) &lt; 0) return Search(name, r-&gt;getLChild()); else return Search(name, r-&gt;getRChild()); } } else return NULL; } //main.cpp MyClass mc1("Tree","This is a tree"); MyClass mc2("Book","This is a book"); MyClass mc3("Zoo","This is a zoo"); BST tree; tree.Insert(mc1); tree.Insert(mc2); tree.Insert(mc3); MyClass * mc = tree.Search("Book"); if (mc != NULL) cout &lt;&lt; mc-&gt;getname() &lt;&lt; endl; </code></pre> <p>The problem is at the MyClass object (mc) returned from Search function.</p> <p>I trace into Search() and make sure "r->getItem()" get what I want.</p> <p>anything wrong with "return &amp;(r->getItem());" ?</p> <p>Thanks!</p> <p>++++++</p> <p>I'm a little bit confused.. can I change to "DataType BST::Search(const string name)" instead of "DataType * BST::Search(const string name)"....it seems that the compiler cannot pass. the return NULL will have some problem...</p> <p>but I try your method to change the DataType* Node::getIthem() it still have error....@@</p>
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    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USvyegorov
    1. USuser1371541
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
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      1. PTAnswer
    2. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. COwhat does `Node::getItem()` return?
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      1. POBinary Search Tree - search function return object (C++)
      1. USjuanchopanza
    2. COif getItem() returns MyClass (not MyClass&), then "return &(r->getItem());" returns an address to a temporary object, which is destroyed at the time of accessing it. Other returns should be blocked by the compiler.
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      1. POBinary Search Tree - search function return object (C++)
      1. USstefaanv
 

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