C + + Road set sail--hands

C + + first-order pointers

Defined

Store type name data type * pointer variable name;

Eg:int *a;//defines a pointer to an integral type A;

How to use pointers

int a,*b;

b=&a;//indicates that the address of a is assigned to B;

*b=5; Assign a value of 5 to the address pointed to by the B pointer, which is equivalent to a=5;

A valid value must be assigned before the pointer is used        int *a,b;         *a=5;//This expression is wrong, because a is not initialized, and assign values. void *a//Universal pointer, can accept any type of pointer,     int *a;     void *b;     char *c;  &nbsp ;     b=a;//is correct, because the void pointer can accept any type of pointer         a=b;//error because the void pointer cannot be directly assigned to other type pointers the correct wording should be a= (int *) b , convert b coercion type to shaping pointer, copy;        c= (char *) b;//correct;  second-order pointer//second-hand pointer, as the name implies, is both pointer-pointing;      & nbsp; Definition: Storage type Data type * * pointer variable name          eg  int **p;//Second-order pointer           &NBS P     #include <iostream>using namespace Std;int main () {int i,*q,**p;  i=123,q=&i,p=&q;// Simply explain the second-order pointer, Cout<<**p;return 0;} Pointer function pass value      void swap (int *x,int *y) {}int main () {int a,b,*p=&a,*q=&b;swap (P,Q); Swap (&a, &AMP;B);  pointer array with array pointer       pointer array              int *p[10];// An array of pointer types is defined, and each element in the array isA pointer type;      array pointer              int (*p) [10];//defines a pointer to an array;          #include <iostream> #include <cstdio>using namespace Std;int main () {int a[2][5]={ 1,2,3,4,5,6,7,8,9,0};int (*p) [5]=a;cout<< "*p[1]=" <<*p[1]<<endl;cout<< "* (p[1]+1) =" < <* (p[1]+1) <<endl;char *q[5]={"A", "B", "C", "D", "E"};//pointer array such initialization of Dev will have a warning, but the VC will not have any warning; it is not recommended for readers to use this initialization. cout<< "q[1]=" <<q[1]<<endl;//because Q[10] is an array of pointer types, so the address is stored in Q. return 0;}   pointer functions and function pointers       pointer function//return value is a pointer function;     Definition: type name * Function name (parameter list); Eg:int * MAX (int *x,int *y);  {      Returen *x>*y?x:y;  &nbsp ;}    Function pointers//algorithms basically not in the race, just by the way, the pointer to the function;            definition: function type (* pointer name) (function parameter list);           egint max (int x,int y) {return x>y?x:y;} int min (int x,int y) {return x<y?x:y;} int main () {int a=1,b=2;int (*p) (int,int);p =max, Cout<<p (A, B), or//can also be written as (*p) (A, B), where * operation has no meaning p=min; Cout<<p (A , b); return 0;  }  pointers and Arrays     C + + array names are both an address, so you can assign values to pointer variables;      eg          int a[ 10];*p;          p=a;//correct;        Two-dimensional array-special second-order pointer;        &N Bsp   int b[10][10];            use two-dimensional arrays as matrices;            B as second-order pointers ;              &NBSP;B refers to the line, called the row pointer;              &NB SP; Perform a * operation on B and convert to a column pointerTo determine where each element is located.              int a[10][10],**b;                  b=a;//this way is wrong.  

C + + Road set sail--pointer