Question

What (if anything) is wrong with the following code? char string_var[] = "Hello"; strcat(string_var, " and Good-bye."); cout \(<<\) string_var Assume that the code is embedded in a complete program, and that an include directive for \(\) is in the program file.

Short answer

The error lies in the allocation of memory for the target array during concatenation using the strcat() function. The target array 'string_var' has only been assigned the memory required to store "Hello" and the null character, which is not sufficient for the resulting concatenated string. To fix the error, sufficient memory should be allocated for the 'string_var' array to hold both "Hello" and " and Good-bye." strings and the null character. This can be done by creating a character array with an appropriate size. In the corrected version of the code, a character array 'string_var' with size 30 is created to hold both strings and the null character, allowing the strcat() function to work correctly and output "Hello and Good-bye.".

Step-by-step solution

Identify the problematic components

In the given code snippet, there is an error related to memory allocation and string concatenation. The programmer tries to concatenate the string " and Good-bye." to the existing string "Hello" without allocating sufficient memory for the resulting string.

Explain the issue with strcat()

The strcat() function concatenates two strings. It takes two arguments, the destination string and the source string. The function appends the source string to the end of the destination string. However, the error here lies in the lack of adequate memory allocated to the target array 'string_var'. It has only been assigned the memory required to store "Hello" and the null character.

Correct the code

To fix this error, we need to allocate sufficient memory for the 'string_var' array to hold both "Hello" and " and Good-bye." strings and the null character. We can use a character array and specify its size accordingly. Here's the corrected version of the code: ```c++ #include #include int main() { char string_var[30] = "Hello"; // Allocate enough memory for both strings strcat(string_var, " and Good-bye."); // Concatenate the strings std::cout << string_var; // Print the resulting string return 0; } ``` In this corrected code, we create a character array 'string_var' with size 30 to hold both strings and the null character. With this change, the strcat() function works correctly, and the output is "Hello and Good-bye.".