Vector 为类模板
使用例子:
#include <iostream>
#include <vector>
#include <string>
using namespace std;
int main(int argc , char *argv[])
{
vector<string> SS;
SS.push_back("The number is 10");
SS.push_back("The number is 20");
SS.push_back("The number is 30");
cout << "Loop by index:" << endl;
int ii;
for(ii=0; ii < SS.size(); ii++)
{
cout << SS[ii] << endl;
}
cout << endl << "Constant Iterator:" << endl;
vector<string>::const_iterator cii;
for(cii=SS.begin(); cii!=SS.end(); cii++)
{
cout << *cii << endl;
}
cout << endl << "Reverse Iterator:" << endl;
vector<string>::reverse_iterator rii;
for(rii=SS.rbegin(); rii!=SS.rend(); ++rii)
{
cout << *rii << endl;
}
cout << endl << "Sample Output:" << endl;
cout << SS.size() << endl;
cout << SS[2] << endl;
swap(SS[0], SS[2]);
cout << SS[2] << endl;
return 0;
}
编译: g++ example.cpp
需要注意的是 end() 指向最后一个数据的下一个指针,所以不能指向最后一个元素,如:
iter_jj = SS.end(); cout << *iter_jj << endl;
stl vector 实现了动态数组功能,可以存储 基本数据,对象,与list同属于线性容器,优点是获取对象快,缺点是查找慢,
stl vector 模板提供了大量的操作vetror 方法, 包括 初始化,插入,删除,容量相关的方法, 另一块为遍历vector接口iterator.
下面附上 vector模板提供的接口:
构造函数:
Method/operator | Description |
vector<T> v; | Vector declaration of data type "T". |
vector<T> v(size_type n); | Declaration of vector containing type "T" and of size "n" (quantity). |
vector<T> v(size_type n,const T& t); | Declaration of vector containing type "T", of size "n" (quantity) containing value "t". Declaration: vector(size_type n, const T& t) |
vector<T> v(begin_iterator,end_iterator); | Copy of Vector of data type "T" and range begin_iterator to end_iterator. Declaration: template vector(InputIterator, InputIterator) |
与 Size 相关的 methods/operators:
Method/operator | Description |
empty() | Returns bool (true/false). True if empty. Declaration: bool empty() const |
size() | Number of elements of vector. Declaration: size_type size() const |
resize(n, t=T()) | Adjust by adding or deleting elements of vector so that its size is "n". Declaration: void resize(n, t = T()) |
capacity() | Max number of elements of vector before reallocation. Declaration: size_type capacity() const |
reserve(size_t n) | Max number of elements of vector set to "n" before reallocation. Declaration: void reserve(size_t) |
max_size() | Max number of elements of vector possible. Declaration: size_type max_size() const |
Note:
size_type
其他 methods/operators:
Method/operator | Description |
erase() clear() | Erase all elements of vector. Declaration: void clear() |
erase(iterator) erase(begin_iterator,end_iterator) | Erase element of vector. Returns iterator to next element. Erase element range of vector. Returns iterator to next element. Declarations:
|
= Example: X=Y() | Assign/copy entire contents of one vector into another. Declaration: vector& operator=(const vector&) |
< | Comparison of one vector to another. Declaration: bool operator<(const vector&, const vector&) |
== | Returns bool. True if every element is equal. Declaration: bool operator==(const vector&, const vector&) |
at(index) v[index] | Element of vector. Left and Right value assignment: v.at(i)=e; and e=v.at(i); Declaration: reference operator[](size_type n) |
front() v[0] | First element of vector. (Left and Right value assignment.) Declaration: reference front() |
back() | Last element of vector. (Left and Right value assignment.) Declaration: reference back() |
push_back(const T& value) | Add element to end of vector. Declaration: void push_back(const T&) |
pop_back() | Remove element from end of vector. Declaration: void pop_back() |
assign(size_type n,const T& t) | Assign first n elements a value "t". |
assign(begin_iterator,end_iterator) | Replace data in range defined by iterators. Declaration: |
insert(iterator, const T& t) | Insert at element "iterator", element of value "t". Declaration: iterator insert(iterator pos, const T& x) |
insert(iterator pos, size_type n, const T& x) | Starting before element "pos", insert first n elements of value "x". Declaration: void insert(iterator pos, size_type n, const T& x) |
insert(iterator pos, begin_iterator,end_iterator) | Starting before element "pos", insert range begin_iterator to end_iterator. Declaration: void insert(iterator pos, InputIterator f, InputIterator l) |
swap(vector& v2) | Swap contents of two vectors. Declaration: void swap(vector&) |
遍历vector(Iterator) methods/operators: 迭代器
Method/operator | Description |
begin() | Return iterator to first element of vector. Declaration: const_iterator begin() const |
end() | Return iterator to end of vector (not last element of vector but past last element) Declaration: const_iterator end() const |
rbegin() | Return iterator to first element of vector (reverse order). Declaration: const_reverse_iterator rbegin() const |
rend() | Return iterator to end of vector (not last element but past last element) (reverse order). Declaration: const_reverse_iterator rend() const |
++ | Increment iterator. |
-- | Decrement iterator. |