Segmentation fault which accessing a map c++

Question

In continuation to this question I am trying to access a map. But i am getting a segmentation fault. Below is my code:

typedef multimap<string, vector<string> > mos_map;
typedef multimap<string, vector<string> >::iterator mos_map_it;

int main()
{

mos_map mos;
mos_map_it it;

vector<string> v1;

v1.push_back("a");
v1.push_back("b");
v1.push_back("c");
v1.push_back("mo1");

mos.insert(mos_map::value_type(*(v1.end()-1),v1));

for(it=mos.begin();it!=mos.end();it++);
{
cout<<(*it).first<<endl;//seg fault occurs here
}

FWIW, you can write it->first.

R. Martinho Fernandes
– R. Martinho Fernandes

2013-06-28 10:36:50 +00:00
Commented Jun 28, 2013 at 10:36 — R. Martinho Fernandes
– R. Martinho Fernandes, Commented Jun 28, 2013 at 10:36
Even this(it->first) resulted in a core dump

user1939168
– user1939168

2013-06-28 10:37:28 +00:00
Commented Jun 28, 2013 at 10:37 — user1939168
– user1939168, Commented Jun 28, 2013 at 10:37

awesoon · Accepted Answer · 2013-06-28 10:43:35Z

4

for(it=mos.begin();it!=mos.end();it++);
//                                    ^

Your loop has empty body.

Some tips:

Enable warnings:

warning: for loop has empty body [-Wempty-body]
Declare variables only when they are needed:
```
for(auto it = mos.begin(); it != mos.end(); it++);
{
    cout << (*it).first << endl;
}
```
This code will cause a compile time error:

error: use of undeclared identifier 'it'

edited Jun 28, 2013 at 10:43

answered Jun 28, 2013 at 10:37

awesoon

33.8k14 gold badges81 silver badges103 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

awesoon Over a year ago

@BalogPal, Yeah, I was adding it :)

Collectives™ on Stack Overflow

Segmentation fault which accessing a map c++

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related