[C++知识库][c++] vector初始化、赋值、访问元素

初始化

vector<int>ivec1(10,42); //内置方法，初始化的内容为10个42
vector<int>ivec2(10);  
  
vector<int>::size_type ix=0;  
  
for(ix;ix<10;++ix)  
  
{  
  
  ivec2[ix]=42; //下标操作 
}

对于vector第一个元素访问的几种方法

cout << "first element from subscript:" << ivec[0] << endl;
cout << "first element from front(): " << ivec.front() << endl;
cout << "first element from begin(): " << *ivec.begin() << endl;
cout << "first element from at(): " << ivec.at(0) << endl;

赋值

int myarray[5] = {1,3,5,7,9};  
vector<int> myvector(myarray , myarray+5);

   vector<int>ivec5;   
  
   vector<int>::size_type cnt=1;  
  
   for(cnt;cnt<=10;++cnt)  
  
   {  
  
      ivec5.push_back(42); //push_back()添加值为的元素到当前vector末尾  
  
   }  

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