How to read csv file cell by cell in c++?

Question

I am still beginner, I would ask if there is a way to read a csv file with c++ cell by cell via for example two nested loop, the outer for loop iterates over the rows, and the inner for-loop iterates over the columns.
e.g. int getValue(row,columm){
int value;

//here should be the code for example
return value;}

Then one would call this, e.g. getValue(4,10) then it returns the value at the 4th row and at the 10th column

My goal if I find such a function, I would create a 2D array, each 1D array of it, has two pair (row,column) then I enter my wanted paired and iterate over the function to obtain finally a list of row, column, its picked value
row,column,its picked value
And finally I can export it to csv file
I searched in google, but it is advanced to me, I didnt found what I looked for, any help please to find such a function as described above?

Answer 1

As promised (a little late), a very simple approach. Obviously you'll need to add error handling, etcetera, but this should give you a clue (documented):

https://code.sololearn.com/cFgKSHmk8II1/?ref=app

Answer 2

nonzyro
I don't know how to thank you, you are my champion ;)
That fixed the problem, I am fond of programming and I hope that I make my knowledge better.
Thank you so much :)

Answer 3

Bookmarking thread. Will post code tomorrow if nobody else has.

Answer 4

You can save the entire csv file in a matrix of strings, and print the element at (i,j) from the matrix.

Here is a sample code :
https://code.sololearn.com/c8mbun90l7HR/?ref=app
Here is something you can try here itself.
https://code.sololearn.com/cxF7H9KwwAF3/?ref=app

Answer 5

I have added an if which will prevent the runtime error.

As for the warning, it can be ignored. I had, by default, disabled the option of extra ISO C++ warnings.

Answer 6

nonzyro
Thank you for your efforts, it looks like perfect, but it doesn't compile.

This is the error:

At line 74 column 24:
no viable conversion from 'std::string' (aka 'basic_string<char>') to 'const char *'

Answer 7

Khaled That's strange, I tested it on my PC. It even compiles on the Playground. Are you using a GNU =>6 compiler? MS compilers make trouble sometimes and I've no Windows machine to test.

Anyway, just change "this->fname" to "this->fname.c_str()" -- that should fix it.

Answer 8

Kinshuk Vasisht thanks for your time.
it doesn't work, it gives after compiling and running:

terminate called after throwing an instance of 'std::out_of_range'
_ what(): basic_string :substr

also there are so many warnings for your code, I provide below them all:

implicit conversion change signedness: 'int' to 'size_type' (aka 'unsigned int')

Line Column
37 10
39 14
39 23
39 26
41 10
43 14
43 23
43 26
46 16
49 16

comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned int')

Line Column
36 18
38 20
40 18
42 20
44 18
47 18

Answer 9

Ok thanks again, I ignored all the warnings, I put my csv location to open.

https://code.sololearn.com/c4TlC2qie7Kh/?ref=app

I run it, it remains writing running without any result.
Could you give me a example inside the code e.g. to get the value at 2nd row and at the 3rd column? in order to see how it will work?

muster.csv

11,12,13,14,15,16,17,18,19
21,22,23,24,25,26,27,28,29
....
etc
Thanks in advance