CODEWITHSUNDEEP
c++cc++11
hhh
hhh

Reputation: 13

extract data from sscanf

I am wondering why sscanf does not work correctly. Here is the case

I have a string "1,2,3,#" and I want to extract the data without comma, the code is 

int a1,a2,a3;
char s;
string teststr = "1,2,3,#";
sscanf(teststr.c_str(), "%d,%d,%d,%s",&a1,&a2,&a3,&s);
cout << teststr << endl;
cout << a1 << a2 << a3 << s << endl;

the expected output should be 123#, but the real result I got is 120# that a3 is always 0.

If I expand to 4 numbers,

int a1,a2,a3,a4;
char s;
string teststr = "1,2,3,4,#";
sscanf(teststr.c_str(), "%d,%d,%d,%d,%s",&a1,&a2,&a3,&a4,&s);
cout << teststr << endl;
cout << a1 << a2 << a3 << a4 << s << endl;

Then the result becomes 1230#. It seems like the last int is always 0. Why will this happen? How to fix it?

Upvotes: 0

Views: 76

Answers (1)

ameyCU
ameyCU

Reputation: 16607

sscanf(teststr.c_str(), "%d,%d,%d,%s",&a1,&a2,&a3,&s);
                                   ^  passing char variable s to %s (specifier for reading single char is %c not %s)

Instead try this -

sscanf(teststr.c_str(), "%d,%d,%d,%c",&a1,&a2,&a3,&s);

Upvotes: 2

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