Integer comparisons (-eq, -ne, -gt, -lt, -ge, -le) in Bash Scripting - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if variable x equals 10.

Bash Scripting

if [ "$x" [1] 10 ]; then echo "Equal"; fi

Drag options to blanks, or click blank then click option'

A-eq

B-ne

C-gt

D-lt

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-ne' which means 'not equal'.

Using '-gt' or '-lt' which check greater or less than.

The operator '-eq' checks if two integers are equal in bash.

2fill in blank

medium

Complete the code to check if variable y is greater than 5.

Bash Scripting

if [ "$y" [1] 5 ]; then echo "Greater"; fi

Drag options to blanks, or click blank then click option'

A-ne

B-gt

C-eq

D-le

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-le' which means 'less than or equal'.

Using '-eq' which means 'equal'.

The operator '-gt' means 'greater than' in bash integer comparisons.

3fill in blank

hard

Fix the error in the code to check if z is less than or equal to 20.

Bash Scripting

if [ "$z" [1] 20 ]; then echo "Less or equal"; fi

Drag options to blanks, or click blank then click option'

A-lt

B-ge

C-ne

D-le

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-lt' which means strictly less than.

Using '-ge' which means greater than or equal.

The operator '-le' means 'less than or equal to' in bash integer comparisons.

4fill in blank

hard

Fill both blanks to check if variable a is not equal to 0 and greater than 10.

Bash Scripting

if [ "$a" [1] 0 ] && [ "$a" [2] 10 ]; then echo "Valid"; fi

Drag options to blanks, or click blank then click option'

A-ne

B-eq

C-gt

D-lt

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-eq' instead of '-ne' for not equal.

Using '-lt' instead of '-gt' for greater than.

Use '-ne' to check not equal and '-gt' to check greater than.

5fill in blank

hard

Fill all three blanks to create a condition that checks if b is greater or equal to 5, less than 15, and not equal to 10.

Bash Scripting

if [ "$b" [1] 5 ] && [ "$b" [2] 15 ] && [ "$b" [3] 10 ]; then echo "In range and valid"; fi

Drag options to blanks, or click blank then click option'

A-ge

B-lt

C-ne

D-eq

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-gt' instead of '-ge' for greater or equal.

Using '-le' instead of '-lt' for less than.

Using '-eq' instead of '-ne' for not equal.

Use '-ge' for greater or equal, '-lt' for less than, and '-ne' for not equal.

Practice

1. Which operator checks if two integers are equal in a bash script?

easy

A. -gt

B. -ne

C. -lt

D. -eq

Solution

1. Step 1: Understand the meaning of each operator

   -eq means equal, -ne means not equal, -gt means greater than, -lt means less than.

2. Step 2: Identify the operator for equality

   The operator that checks if two integers are equal is -eq.

3. Final Answer:

   -eq -> Option D

4. Quick Check:

   Equality check = -eq [OK]

Hint: Remember: eq means equal, ne means not equal [OK]

Common Mistakes:

• Confusing -eq with -ne
• Using == instead of -eq in [ ]
• Forgetting spaces around operators

2. Which of the following is the correct syntax to check if variable x is greater than 10 in bash?

easy

A. [ $x > 10 ]

B. [ $x -gt 10 ]

C. [ $x -ge 10 ]

D. [ $x => 10 ]

Solution

1. Step 1: Recall integer comparison operators in bash

   For greater than, bash uses -gt inside [ ]. The symbol > is for string comparison or redirection.

2. Step 2: Check each option

   [ $x -gt 10 ] uses [ $x -gt 10 ] which is correct syntax for integer greater than check.

3. Final Answer:

   [ $x -gt 10 ] -> Option B

4. Quick Check:

   Greater than check uses -gt [OK]

Hint: Use -gt for greater than, not > inside [ ] [OK]

Common Mistakes:

• Using > instead of -gt inside [ ]
• Using => instead of -ge
• Missing spaces around brackets and operators

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

num=5
if [ $num -lt 10 ]; then
echo "Less"
else
echo "More"
fi

medium

A. Less

B. More

C. Syntax Error

D. No output

Solution

1. Step 1: Evaluate the condition [ $num -lt 10 ]

   num is 5, 5 is less than 10, so condition is true.

2. Step 2: Determine which branch runs

   Since condition is true, the then branch runs and prints "Less".

3. Final Answer:

   Less -> Option A

4. Quick Check:

   5 < 10 is true, prints Less [OK]

Hint: If condition true, then branch runs; else runs otherwise [OK]

Common Mistakes:

• Confusing -lt with -le
• Forgetting spaces inside [ ]
• Using > instead of -lt

4. Identify the error in this bash snippet:

count=3
if [ $count -gt 5 ]
then
  echo "High"
fi

medium

A. No error, script runs fine

B. Missing semicolon or newline after condition

C. Missing spaces around brackets

D. Wrong operator -gt used

Solution

1. Step 1: Check if the if condition syntax is correct

   The if condition line ends with ] but the next line is then. Bash requires a newline or semicolon after ] before then.

2. Step 2: Identify the fix

   Add a newline (already present) or a semicolon after ] to separate condition and then. Here newline is present, so syntax is correct.

3. Step 3: Re-examine the snippet

   Actually, the snippet as shown is correct syntax if newline is present after ] before then. If newline missing, error occurs.

4. Final Answer:

   No error, script runs fine -> Option A

5. Quick Check:

   if condition must end with newline or semicolon before then [OK]

Hint: Put newline or semicolon after ] before then [OK]

Common Mistakes:

• Writing if [ condition ] then on same line without semicolon
• Forgetting spaces inside [ ]
• Using > instead of -gt

5. You want to write a bash script that prints "Valid" only if a variable age is between 18 and 30 inclusive. Which condition correctly checks this?

hard

A. [ $age -ge 18 -a $age -le 30 ]

B. [ $age -gt 18 -o $age -lt 30 ]

C. [ $age -ge 18 ] && [ $age -le 30 ]

D. [ $age -gt 18 -a $age -lt 30 ]

Solution

1. Step 1: Understand the range condition

   We want age >= 18 and age <= 30 inclusive, so both conditions must be true.

2. Step 2: Analyze each option

   [ $age -ge 18 -a $age -le 30 ] uses -a inside single [ ], which is valid but less recommended. [ $age -gt 18 -o $age -lt 30 ] uses -o (or), which is wrong. [ $age -ge 18 ] && [ $age -le 30 ] uses two separate [ ] with &&, which is correct and clear. [ $age -gt 18 -a $age -lt 30 ] uses > and < (not inclusive) and -a inside [ ].

3. Final Answer:

   [ $age -ge 18 ] && [ $age -le 30 ] -> Option C

4. Quick Check:

   Use && with separate [ ] for clear inclusive range [OK]

Hint: Use && with separate [ ] for AND conditions [OK]

Common Mistakes:

• Using -o (OR) instead of AND
• Using > and < instead of -ge and -le
• Combining multiple conditions inside one [ ] with -a (less clear)