CODEWITHSUNDEEP
c++
user6532
user6532

Reputation: 1

Bus error in printf for printing the member of structure

struct abc
{
    float b;
};

abc* xyz;

xyz->b = 10;
printf("%f", xyz->b);

error at printf. What is the reason? How can I solve this?

Upvotes: 0

Views: 232

Answers (3)

Pepijn Kramer
Pepijn Kramer

Reputation: 13076

In code :

#include <iostream>

struct abc
{
    float b = 0.0f; // initialize!
};

int main()
{
    abc* xyz = new abc{}; // <-- new!
    // or use auto xyz = std::make_unique<abc>(); <-- recommended for c++

    xyz->b = 10.0f; 
    std::cout << xyz->b;
    // printf("%f", xyz->b); <-- std::cout is more 'c++'

    delete xyz;
}

Upvotes: 1

Sajal Mandrekar
Sajal Mandrekar

Reputation: 41

You need to define an instance of structure.

abc *xyz only defines a pointer, it doesn't allocate memory(static or dynamic) for an instance of struct abc. Hence variable float b is not allocated space.

Solution:

abc xyz;
xyz.b=10;

Or

abc *xyz = new abc;

Upvotes: 4

Ralf Ulrich
Ralf Ulrich

Reputation: 1714

One possible solution is to just change: abc *xyz; into abc *xyz = new abc();

The reason for the crash is that you did not allocate any actual memory for abc::b, thus xyz is an uninitialized pointer.

Upvotes: 0

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