45 lines
1.0 KiB
Markdown
45 lines
1.0 KiB
Markdown
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# HashMap::begin / end
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```cpp
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Iterator begin();
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Iterator end();
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ConstIterator begin() const;
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ConstIterator end() const;
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```
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获取哈希表的迭代器。迭代器遍历所有桶中的元素。
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**参数：** 无
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**返回：** 返回指向第一个元素和末尾（最后一个元素之后）位置的迭代器。
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**复杂度：** O(1)
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**示例：**
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```cpp
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XCEngine::Containers::HashMap<int, const char*> map;
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map.Insert(1, "one");
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map.Insert(2, "two");
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map.Insert(3, "three");
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for (auto it = map.begin(); it != map.end(); ++it) {
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std::cout << it->first << " -> " << it->second << std::endl;
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}
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// 输出顺序不确定，取决于哈希桶的内部布局
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// 范围 for 循环（需要 C++20 或手动实现 begin/end）
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for (auto& [key, value] : map) {
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std::cout << key << " -> " << value << std::endl;
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}
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// 常量迭代器
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for (auto it = map.cbegin(); it != map.cend(); ++it) {
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std::cout << it->first << " -> " << it->second << std::endl;
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}
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```
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## 相关文档
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- [HashMap 总览](hashmap.md) - 返回类总览
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