CODEWITHSUNDEEP
c++ioofstream
aborocz
aborocz

Reputation: 199

error writing to file with ofstream

I have a problem with writing number to a file with ofstream. When i write numbers there are characters like this █ instead of numbers. The method i write to the file is:

byte _b = 20;
ofstream p_file;
p_file.open("txt.txt", std::ios::app);
p_file << _b;

Is there any way to be right, or just use another filewriter method? Thanks.

EDIT:

p_file << (int) _b;

works fine. Thanks

Upvotes: 0

Views: 612

Answers (3)

R. Martinho Fernandes
R. Martinho Fernandes

Reputation: 234384

I bet that byte is char or some variant thereof. In that case you are setting _b to the character with code 20, which in ASCII is a control character. The stream output will try to output the character not the number.

You can cast it to another integral type if you want to obtain the number:

p_file << static_cast<int>(_b);

Upvotes: 6

Alok Save
Alok Save

Reputation: 206518

Change 

byte _b = 20;

to 

int _b = 20;

byte is probably typedef to char somewhere in your code.

Upvotes: 0

Sarfaraz Nawaz
Sarfaraz Nawaz

Reputation: 361322

What is byte in your code? I assume it is a typedef of unsigned char. Note C++ doesn't have byte as data-type.

If so, then p_file prints a character whose ASCII value is 20. That is what you see in the file.

Do this if you want it to print 20 instead :

p_file << (int)_b;

Or, simply change the data type of _b from byte to int.

Upvotes: 2

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