pointer1

The Unknown Word

The First	The Second
videoinput library	视频输入库
crocodil	['kra:kedail]鳄鱼
preprocessor	预处理器 [pri:'prousese(r)]
novice	['na:vis]初学者，新手，
intimidate	恐吓，威胁[in'timideit]
declaration	[dekle'reition]声明，宣言
used	[ju:st]习惯于
SDK	software development kit 软件开发工具
version selector	版本选择器
xproj	新一代的项目文件，是XML的格式

Arguments to main

Arguments is often a novice programmers' first encounter with pointers to array to pointers and can prove intimidating.

• argv is used to refer to an array of strings,its declaration will look like this:

char*argv[]	//equivalent to to that show above:char **argv
int main(int argc,char *argv[])		//int main(int argc,char **argv)

p++、(p)++、++p、++p ——the difference

int a[5]={1,2,3,4,5};
int *p = a;

• *p++ Firstly,get the value to which p ponints(The first element p points to),and increase the pointer p by 1.

        cout << *p++; // the result is 1

        cout <<(*p++);  // the result is 1

• (*p)++ Firstly,get the value the pointer p points to(the first element of the array),and increase the value by 1(the first element of array is 2).

        cout << (*p)++; //  1
        cout <<((*p)++);  //2

• *++p Firstly,increase the pointer p by 1(At this point,point to the second element of the array),and the operator * gets the value.

        cout << *++p; //  2
        cout <<(*++p)  //2

• ++*p get the value pointer p points to(the first element of the array),and the value increase by 1(the element become 2).

      cout <<++*p; //   2    
        cout <<(++*p)  //2

---

#include<iostream>
int main(){
int a[5]={1,2,3,4,5};
int *p=a;
cout<<p<<endl;
cout<<*p++<<endl;
cout<<(*p++)<<endl;
return 0;
}