break and continue in Bash Scripting - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the break command do in a Bash loop?

The break command immediately stops the loop and exits it, skipping any remaining iterations.

beginner

What is the purpose of the continue command in a Bash loop?

The continue command skips the rest of the current loop iteration and moves to the next iteration.

intermediate

How would you use break inside a for loop to stop when a condition is met?

Inside the loop, use an if statement to check the condition. If true, run break to exit the loop immediately.

beginner

Explain the difference between break and continue in Bash loops.

break stops the entire loop immediately. continue skips only the current iteration and continues with the next one.

advanced

Can break and continue be used in nested loops in Bash? How?

Yes. break and continue affect only the innermost loop by default. You can specify a number to affect outer loops, e.g., break 2 breaks two loops.

What happens when break is executed inside a Bash loop?

A Nothing happens; the loop continues normally.

B The current iteration is skipped, and the loop continues.

C The loop restarts from the beginning.

D The loop stops immediately and exits.

break stops the loop immediately and exits it.

Which command skips the rest of the current loop iteration and moves to the next one?

A continue

B exit

C stop

D break

continue skips the rest of the current iteration and proceeds to the next.

In a nested loop, what does break 2 do?

A Breaks only the innermost loop.

B Breaks two levels of loops, exiting both.

C Skips two iterations of the current loop.

D Causes an error.

break 2 exits two nested loops at once.

What will this script print?

for i in 1 2 3; do
  if [ "$i" -eq 2 ]; then
    continue
  fi
  echo $i
done

A 1 3

B 2 3

C 1 2 3

D 1 2

When i equals 2, continue skips printing it, so only 1 and 3 print.

Which command would you use to stop a loop immediately when a condition is met?

A exit

B continue

C break

D skip

break stops the loop immediately.

Describe how break and continue control the flow inside Bash loops.

Think about what happens to the loop after each command runs.

Explain how to use break and continue in nested loops in Bash.

Consider how many loops you want to exit or skip.

Practice

1. What does the break command do inside a bash loop?

easy

A. Pauses the loop until user input

B. Stops the loop immediately and exits it

C. Restarts the loop from the beginning

D. Skips the current iteration and continues with the next

Solution

1. Step 1: Understand the role of break in loops

   The break command immediately stops the loop and exits it, no matter where it is in the loop.

2. Step 2: Compare with other commands

   continue skips to the next iteration, but break stops the loop entirely.

3. Final Answer:

   Stops the loop immediately and exits it -> Option B

4. Quick Check:

   break stops loop = D [OK]

Hint: Break means stop loop now, continue means skip one round [OK]

Common Mistakes:

• Confusing break with continue
• Thinking break skips iteration instead of stopping
• Assuming break restarts the loop

2. Which of the following is the correct syntax to skip the current iteration in a bash for loop?

easy

A. break

B. skip

C. continue

D. next

Solution

1. Step 1: Identify the command to skip iteration

   In bash, continue is used to skip the current iteration and move to the next one.

2. Step 2: Check other options

   break stops the loop, skip and next are not valid bash commands.

3. Final Answer:

   continue -> Option C

4. Quick Check:

   Skip iteration = continue [OK]

Hint: Use continue to skip current loop round in bash [OK]

Common Mistakes:

• Using break instead of continue
• Using non-existent commands like skip or next
• Confusing syntax with other languages

3. What will be the output of this bash script?

for i in 1 2 3 4 5; do
  if [ "$i" -eq 3 ]; then
    break
  fi
  echo $i
done

medium

A. 1 2 3 4 5

B. 3 4 5

C. 1 2 3

D. 1 2

Solution

1. Step 1: Analyze the loop and break condition

   The loop runs from 1 to 5. When i equals 3, the break command stops the loop immediately.

2. Step 2: Determine which values are printed

   Before reaching 3, the script echoes 1 and 2. When i is 3, loop breaks, so 3 is not printed.

3. Final Answer:

   1 2 -> Option D

4. Quick Check:

   Break stops at 3, prints before = 1 2 [OK]

Hint: Break stops loop before printing current value [OK]

Common Mistakes:

• Including the break value in output
• Confusing break with continue
• Assuming loop runs fully

4. Identify the error in this bash script snippet:

for i in 1 2 3 4; do
  if [ $i -eq 2 ]
    continue
  fi
  echo $i
done

medium

A. Missing then keyword after if condition

B. Missing semicolon before continue

C. continue cannot be used inside if

D. echo command is misplaced

Solution

1. Step 1: Check if statement syntax

   The if statement requires a then keyword after the condition before commands.

2. Step 2: Identify missing keyword

   The script misses then after [ $i -eq 2 ], causing syntax error.

3. Final Answer:

   Missing then keyword after if condition -> Option A

4. Quick Check:

   If needs then before commands [OK]

Hint: Always put then after if condition in bash [OK]

Common Mistakes:

• Omitting then after if
• Assuming continue needs semicolon
• Thinking continue can't be inside if

5. You want to print numbers 1 to 5 but skip 3 and stop the loop if number is greater than 4. Which code snippet achieves this?

hard

A. for i in 1 2 3 4 5; do
if [ "$i" -eq 3 ]; then continue; fi
if [ "$i" -gt 4 ]; then break; fi
echo $i
done

B. for i in 1 2 3 4 5; do
if [ "$i" -gt 4 ]; then continue; fi
if [ "$i" -eq 3 ]; then break; fi
echo $i
done

C. for i in 1 2 3 4 5; do
if [ "$i" -eq 3 ]; then break; fi
if [ "$i" -gt 4 ]; then continue; fi
echo $i
done

D. for i in 1 2 3 4 5; do
if [ "$i" -eq 3 ]; then continue; fi
if [ "$i" -gt 4 ]; then continue; fi
echo $i
done

Solution

1. Step 1: Understand requirements

   Skip printing 3 (use continue), stop loop if number > 4 (use break).

2. Step 2: Analyze each option

   for i in 1 2 3 4 5; do if [ "$i" -eq 3 ]; then continue; fi if [ "$i" -gt 4 ]; then break; fi echo $i done correctly uses continue to skip 3 and break to stop after 4. Others misuse break and continue or reverse conditions.

3. Final Answer:

   Option A code snippet -> Option A

4. Quick Check:

   continue skips 3, break stops after 4 [OK]

Hint: Use continue to skip, break to stop loop [OK]

Common Mistakes:

• Swapping break and continue logic
• Wrong condition order causing wrong output
• Not stopping loop after number > 4