STL
容器
序列式
关联式
#include<iostream>
using namespace std;
#include"vector"
#include"algorithm"
void main1()
{
//1.容器，把元素拷贝到容器中
vector<int> v1;
v1.push_back(-1);
v1.push_back(1);
v1.push_back(2);
v1.push_back(1);
v1.push_back(3);
v1.push_back(4);
v1.push_back(5);
//访问容器
//2.迭代器，相当于一个指针
for (vector<int>::iterator it = v1.begin(); it != v1.end(); it++)
{
cout << *it << " ";
}
//3.算法
int num = count(v1.begin(), v1.end(), 1);
cout << "num:" << num << endl;
}
void main()
{
main1();
system("pause");
}
string
string 是一个类
```#include<iostream>
using namespace std;
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#include"string"
//字符串的初始化
void main21()
{
string s1 = "abc";
string s2("qwe");
string s3 = s2;
string s4(11, 'a');//11个a
cout << s1 << endl;
cout << s2 << endl;
cout << s3 << endl;
cout << s4 << endl;
}
//字符串的遍历
void mian22()
{
string s1 = "abcd";
for (int i = 0; i < s1.length(); i++)
{
cout << s1[i] << " ";
}
cout << endl;
for (string::iterator it = s1.begin(); it != s1.end(); it++)
{
cout << *it << " ";
}
cout << endl;
for (int i = 0; i < s1.length(); i++)
{
cout << s1.at(i) << " ";// 抛出异常
}
cout << endl;
try
{
for (int i = 0; i < s1.length()+3; i++)
{
cout << s1.at(i) << " ";// 抛出异常
}
}
catch (...)
{
cout << "异常" << endl;
}
cout << endl;
/*程序会异常结束
try
{
for (int i = 0; i < s1.length()+3; i++)
{
cout << s1[i] << " ";
}
cout << endl;
}
catch (...)
{
cout << "异常" << endl;
}*/
}
void main()
{
// main21();
mian22();
system("pause");
}
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//字符指针和string的转换
void main23()
{
string s1 = "aaa";
//s1=>char *
printf("s1:%s\n", s1.c_str());
//s1内容copy到buff
char buff[128];
//s1.copy(buff, 3, 0);
//cout << "buff" << buff << endl;
}
void main24()
{
string s1 = "abc";
string s2 = "efg";
s1 = s1 + s2;
cout << "s1"<<s1 << endl;
string s3 = "abc";
string s4 = "efg";
s3.append(s4);
cout << "s4" << s3 << endl;
}
void main25()
{
string s1 = "hello c++ hello world hello xiaoy";
int index = s1.find("hello", 5);
cout << "index"<<index << endl;
int offindex = s1.find("hello", 0);
while (offindex != -1)
{
cout << offindex << endl;
offindex++;
offindex = s1.find("hello", offindex );
}
//替换
offindex = s1.find("hello", 0);
while (offindex != -1)
{
cout << offindex << endl;
s1.replace(offindex, 5, "Hello");
offindex++;
offindex = s1.find("hello", offindex);
}
cout << "替换后的" << s1 << endl;
}
//插入
void main26()
{
string s1 = "bbb";
s1.insert(1, "aaa");
cout << s1 << endl;
}
void main27()
{
string s1 = "AAAbbb";
transform(s1.begin(), s1.end(), s1.begin(), toupper);
cout <<"s1" <<s1 << endl;
string s2 = "AAAbbb";
transform(s2.begin(), s2.end(), s2.begin(), tolower);
cout << "s2" << s2 << endl;
}