C++ 栈和堆 new和delete

1.       数组内存空间分配在栈内

        栈                                        堆

myA[0]…myA[4]

 

2.       int* myAPtr = new int [5]

    栈                                        堆

myAPtr    ---------->  myAPtr [0]… myAPtr [4]

 

3.       char** myAPtr=new char*[5]

for(int i=0;i<5;i++)

{

myAPtr[i]=new char[10];

  }

for(int i=0;i<5;i++)

{

delete [] myAPtr[i];

 }

delete[] myAPtr;

 

    栈                                                            堆

myAPtr    ---------->   myAPtr [0] ----------> myAPtr [0][0]

                                       …                      …

                                 myAPtr [4]                myAPtr[0] [4]

 

4. 字符串"hello"分配的是只读内存

    inString[0]=‘a';             //Crash! Attempt to write to read-only memory

 

5. char instring[] = "hello";    //Copy, 因为基于栈的变量在任何情况下都不能引用其它地方的内存

  instring[0] =’a'；    //Correct