no suitable conversion from "std::string" to "char" exists

Question

I'm working on a project for school and I am running into a bit of a problem (error is in the title).

Here is the line of code that runs into the error:

kruskalS[n].nodeList[m].push_back(tempFirstCity);

kruskalS is a struct and nodeList is a vector of type string within the struct and I'm trying to insert tempFirstCity (also a string) into that array.

I could easily be making a basic mistake since I haven't done any programming since April. Any kind of help would be appreciated and I'm willing to post a bit more information from the program if needed.

aschepler · Accepted Answer · 2012-12-01 05:27:09Z

5

A std::string is (sort of) a container of chars. A push_back function is used to add one element to the end of a container. So when you call kruskalS[n].nodeList[m].push_back(tempFirstCity);, you say you are trying to add one element to the end of the string called kruskalS[n].nodeList[m]. So the compiler expects that one element to be a char.

If you know that tempFirstCity is not empty and you want to add the first char from tempFirstCity to the end of kruskalS[n].nodeList[m] (including the case where you know tempFirstCity.size() == 1), you can do

kruskalS[n].nodeList[m].push_back(tempFirstCity[0]);

If you want to add the entire string after any current contents, you can do

kruskalS[n].nodeList[m] += tempFirstCity;

If you expect there are no current contents and/or you want to just replace anything already there with the tempFirstCity string, you can do

kruskalS[n].nodeList[m] = tempFirstCity;

answered Dec 1, 2012 at 5:27

aschepler

72.5k11 gold badges114 silver badges174 bronze badges

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

5 Comments

wjmolinam Over a year ago

Similarly, if tempFirstCity.size() > 1, then he could also use kruskalS[n].nodeList[m].append(tempFirstCity); just as well as kruskalS[n].nodeList[m] += tempFirstCity;.

user1868095 Over a year ago

would there be anything better than a vector for holding a list of strings?

ildjarn Over a year ago

@user1868095 : That depends entirely on your specific requirements, but vector is generally the best starting point if no requirements are yet known,.

user1868095 Over a year ago

there shouldn't be a limit, it does need to hold names of Cities if that matters

ildjarn Over a year ago

@user1868095 : Who said 'limit'? Requirements means algorithmic/space complexities for lookup, insertion, deletion, whether random access traversal is needed, etc. These are very fundamental data structure concepts, and are the core differentiaters between different standard library containers.

Alok Save · Accepted Answer · 2012-12-01 04:58:23Z

5

You can use:

std::string::c_str()

It returns a const char *.

answered Dec 1, 2012 at 4:58

Alok Save

208k56 gold badges449 silver badges540 bronze badges

4 Comments

user1868095 Over a year ago

where and how should i implement it?

Alok Save Over a year ago

@user1868095: Check the reference and how to use it, then try to apply to your use case. If you do that you will learn something as well.

user1233508 Over a year ago

Based on OP's description I imagine the goal is to add a new element into nodeList, not append it to an existing element.

ildjarn Over a year ago

-1 There is no overload of basic_string<>::push_back that takes a CharT const*, only a CharT.

acraig5075 · Accepted Answer · 2012-12-01 05:55:40Z

0

You say nodeList is an array of type string. i.e. std::string nodeList[x] where x is a constant.

Then assigning a new element to that array where m < x is as follows:

kruskalS[n].nodeList[m] = tempFirstCity;

Based on comments:

For appending to end of vector you don't need the index m:

kruskalS[n].nodeList.push_back(tempFirstCity);

For inserting at index m:

vector<string>::iterator itr = nodeList.begin();
for (int i = 0; i < m; i++)
  itr++;
nodeList.insert(itr, tempFirstCity);

edited Dec 1, 2012 at 5:55

answered Dec 1, 2012 at 5:37

acraig5075

10.8k3 gold badges33 silver badges52 bronze badges

4 Comments

user1868095 Over a year ago

I meant to say vector not string, if that changes anything

acraig5075 Over a year ago

OK, thats different, then. What do you mean by insert? Do you mean insert somewhere in the middle of the vector, or append to the end?

user1868095 Over a year ago

put it at the end, it's just supposed to be a list of cities

acraig5075 Over a year ago

kruskalS[n].nodeList.push_back(tempFirstCity);

bhuang3 · Accepted Answer · 2012-12-01 04:59:15Z

-2

In C++, you can use string::c_str() to convert a string to C programming char array..

answered Dec 1, 2012 at 4:59

bhuang3

3,6632 gold badges19 silver badges17 bronze badges

3 Comments

user1868095 Over a year ago

where and how should i implement it and do you know why this is happening even though i'm using only strings?

bhuang3 Over a year ago

Because sometimes C++ need to invoke some C API functions, which need C style string as their function parameter..

ildjarn Over a year ago

@bhuang3 : And how does that relate to the code in the question at all?

Collectives™ on Stack Overflow

no suitable conversion from "std::string" to "char" exists

4 Answers 4

5 Comments

4 Comments

4 Comments

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

5 Comments

4 Comments

4 Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related