En anglais

Think it through on paper

Computing · Programming · ages 15-16

Name ______________________ Date ____________

The computer stops at once and points at a line. Which error?
- A logic error
- A syntax error
- A slow computer
What does a trace table hold?
- Only the final output
- The list of keywords
- Each variable's value at each line
A logic error lets the program finish, but the answer is wrong.
Circle one: True False
A loop finishes quietly but totals 41 instead of 42. Which kind?
- A syntax error
- A logic error
- A power cut
A missing colon halts everything before anything runs. Which kind, and why?
- Syntax, since the rules broke
- Logic, since the answer is wrong
- Neither, since colons are optional
Where do you hunt first for a wrong-but-finished program?
- Add more colons everywhere
- Restart and hope
- Trace the lines where values change
Before running a short unknown program, what proves you grasp it?
- Reading its title twice
- A hand trace that predicts its printout
- Counting its lines
A friend blames line 9 for a crash flagged at line 4. What do you say?
- Trust the flagged line, since syntax errors point at the confusion
- Blame the last line of every program
- Ignore messages and rewrite everything

Answer key

For grown-ups. Fold this page away before handing over the rest.

A syntax error · Broken grammar stops the run at once and points at the confusion.
Each variable's value at each line · A trace table records what every name holds as each line runs.
True · No rule broke, so nothing stops, yet the meaning drifted.
A logic error · It ran start to finish, so grammar is fine and the meaning drifted.
Syntax, since the rules broke · A missing colon breaks grammar, so nothing runs at all.
Trace the lines where values change · Hand-tracing values shows where they first drift off track.
A hand trace that predicts its printout · Predicting the printout on paper proves you followed every line.
Trust the flagged line, since syntax errors point at the confusion · The flagged line is where the computer got lost, so start there.