7.9 Identifying and Correcting Errors Cambridge IGCSE 0478

What is a logic error in an algorithm?

• An error that causes the algorithm to produce incorrect results despite running without syntax errors.

• An error caused by incorrect punctuation or spelling in the code.

• An error that prevents the program from running at all.

• An error that occurs due to memory overload.

A syntax error occurs when:

• The code does not follow the correct rules of the programming language.

• The program runs but produces incorrect results.

• A variable is used before being initialized.

• The logic of the algorithm is flawed.

Which of the following is an example of a runtime error?

• Dividing a number by zero during execution.

• Forgetting a semicolon at the end of a line in a program.

• Using an incorrect variable name in an assignment.

• Writing a loop that never executes.

What type of error is caused when an algorithm enters an infinite loop?

• A logic error.

• A syntax error.

• A runtime error.

• A verification error.

Which of the following would cause a syntax error?

• Using a variable before declaring it in a strongly-typed language.

• Forgetting to initialize a variable before using it in calculations.

• Using the wrong formula in an equation.

• Forgetting to update a loop control variable, leading to an infinite loop.

Consider the following incorrect pseudocode: nginx CopyEdit x ← 5 y ← 10 z ← x + y PRINT Z What type of error does this pseudocode contain?

• A syntax error (incorrect capitalization of Z instead of z).

• A runtime error.

• A logic error.

• A validation error.

What is the best way to identify logic errors in an algorithm?

• Perform a dry run using a trace table.

• Use a compiler to detect them.

• Rely on the program to crash and indicate the error.

• Ignore them since they do not stop the program from running.

The following pseudocode contains an error: css CopyEdit total ← 0 FOR i ← 1 TO 5 total ← total + i What is the problem with this algorithm?

• The loop does not have an END FOR or equivalent termination statement.

• The loop does not run the correct number of times.

• The total is not updated correctly.

Which method is most effective for finding syntax errors?

• Using a compiler or interpreter.

• Running the program and checking the output.

• Manually checking the logic of the code.

• Creating a test plan.

Why might an algorithm give an incorrect result despite having no syntax errors?

• It contains a logic error.

• It has missing semicolons.

• The computer misinterpreted the instructions.

• It uses incorrect variable names.