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Which line(s) of the following code fragment will cause a runtime error?

/*Line 1:*/ /*Line 2: */ int ipl = new int (5); ipl; int *ip2 = /*Line 3: */ *ip1 = 10; /*Line 4:*/ cout << *ipl << *ip2 << endl; delete ip2; /*Line 5:*/ /*Line 6:*/ delete ipl;

a. Line 1
B. Line 2
C. Line 3.
D. Line 5 e. Line 6

User Max Shron
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1 Answer

3 votes

Final answer:

Analyzing the code fragment, the line that would cause a runtime error is Line 6, because it attempts to delete memory that was not allocated with 'new' or has already been deleted, leading to undefined behavior.

Step-by-step explanation:

The code fragment provided contains several errors, but the question asks which line will cause a runtime error. Let's analyze the snippet line by line:

  • Line 1 is a comment and will not cause any errors.
  • Line 2 contains the syntax int ipl = new int (5), which is incorrect. In C++, to dynamically allocate memory, you should use int* ip1 = new int(5) instead. However, this is generally a compile-time error, not a runtime error.
  • Line 3 will actually cause a compile-time error because there's an attempt to assign 10 to *ip1 but *ip1 was never declared correctly due to the error on line 2. Nevertheless, if line 2 were correct, line 3 would compile but would not cause a runtime error.
  • Line 4 would also cause a compile-time error because the variables ipl and ip2 were used incorrectly. It should be cout << *ip1 << *ip2 instead of cout << *ipl << *ip2. This is not a runtime error.
  • Line 5: If the allocation was successful and ip2 was assigned a valid memory address, this line is correct and will not cause a runtime error.
  • Line 6: will cause a runtime error because it uses delete on ipl, which should be ip1, and is not a pointer (assuming line 2 was meant to be int* ip1). Even if it was a pointer, it must not be deleted twice, as the same allocation is attempted to be deleted on Line 5 and Line 6, which is undefined behavior.

Considering the errors in the code, the lines that would cause runtime errors, if given a chance to run, would be Line 6 due to the double delete attempt.

User Guness
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8.5k points