概念问题 [英] concept question

问题描述

int main（void）{

char * p;

char q [10];

char temp =''a' ; //这条线在外面


for（int i = 0; i< 10; i ++）{

p =& temp;

p ++;

q [i] =''a'';

}


for（int i = 0; i< 10; i ++）{

cout<< * p ++<<" \t" ;;

cout<< q [ i]<< endl;

}

}


int main（void）{

char * p;

char q [10];

for（int i = 0; i< 10; i ++）{

char temp =''a''; //这条线在里面

p =& temp;

p ++;

q [i] =''a'';

}


for（int i = 0; i< 10; i ++）{

cout<< * p ++< <" \t";

cout<< q [i]<< endl;

}

}


为什么他们的结果不一样？

有人可以帮我解释一下。

非常感谢。


-jiing-

int main(void){
char* p;
char q[10];
char temp=''a''; //This line is outside

for(int i=0;i <10;i++){
p = &temp;
p++;
q[i]=''a'';
}

for(int i=0;i<10;i++){
cout<<*p++<<"\t";
cout<<q[i]<<endl;
}
}

int main(void){
char* p;
char q[10];
for(int i=0;i <10;i++){
char temp=''a''; //This line is inside
p = &temp;
p++;
q[i]=''a'';
}

for(int i=0;i<10;i++){
cout<<*p++<<"\t";
cout<<q[i]<<endl;
}
}

why their result are not the same?
Can someone explain it for me.
Thanks a lot.

-jiing-

推荐答案

jiing写道：

jiing wrote:

for（int i = 0; i< 10; i ++）{
char temp =''a''; //这一行在里面
p =& temp;
p ++;

为什么他们的结果不一样？
有人可以帮我解释一下。

for(int i=0;i <10;i++){
char temp=''a''; //This line is inside
p = &temp;
p++;
why their result are not the same?
Can someone explain it for me.

两个版本都有未定义的行为。你将p分配给& temp然后

递增p。这将导致p指向未定义的地址。

你想做什么？


谢谢，

-

CrayzeeWulf

Both versions have undefined behavior. You are assigning p to &temp and then
incrementing p. This will result in p pointing to an undefined address.
What are you trying to do ?

Thanks,
--
CrayzeeWulf

jiing写道：

jiing wrote:

for（int i = 0; i< 10 ; i ++）{
char temp =''a''; //这一行在里面
p =& temp;
p ++;

为什么他们的结果不一样？
有人可以帮我解释一下。

for(int i=0;i <10;i++){
char temp=''a''; //This line is inside
p = &temp;
p++;
why their result are not the same?
Can someone explain it for me.

两个版本都有未定义的行为。你将p分配给& temp然后

递增p。这将导致p指向未定义的地址。

你想做什么？


谢谢，

-

CrayzeeWulf

Both versions have undefined behavior. You are assigning p to &temp and then
incrementing p. This will result in p pointing to an undefined address.
What are you trying to do ?

Thanks,
--
CrayzeeWulf

jiing写道：

jiing wrote:

for（int i = 0; i< 10 ; i ++）{
char temp =''a''; //这一行在里面
p =& temp;
p ++;

为什么他们的结果不一样？
有人可以帮我解释一下。

for(int i=0;i <10;i++){
char temp=''a''; //This line is inside
p = &temp;
p++;
why their result are not the same?
Can someone explain it for me.

两个版本都有未定义的行为。你将p分配给& temp然后

递增p。这将导致p指向未定义的地址。

你想做什么？


谢谢，

-

CrayzeeWulf

Both versions have undefined behavior. You are assigning p to &temp and then
incrementing p. This will result in p pointing to an undefined address.
What are you trying to do ?

Thanks,
--
CrayzeeWulf

这篇关于概念问题的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！