Indexed array declaration in Bash Scripting - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Output of Indexed Array Declaration and Access

What is the output of this Bash script?

Bash Scripting

arr=(apple banana cherry)
echo ${arr[1]}

A 1

B apple

C cherry

D banana

💡 Hint

Remember that Bash arrays start indexing at 0.

The array 'arr' has elements indexed from 0. So arr[0] is 'apple', arr[1] is 'banana', and arr[2] is 'cherry'. The script prints arr[1], which is 'banana'.

💻 Command Output

intermediate

Length of Indexed Array

What does this Bash command output?

Bash Scripting

arr=(one two three four)
echo ${#arr[@]}

A 4

B 3

C one two three four

D 0

💡 Hint

${#arr[@]} gives the number of elements in the array.

The array has four elements, so ${#arr[@]} outputs 4.

📝 Syntax

advanced

Identify the Correct Indexed Array Declaration

Which option correctly declares an indexed array with elements 'red', 'green', 'blue' in Bash?

A arr={red, green, blue}

B arr=(red green blue)

C arr=[red, green, blue]

D arr='red green blue'

💡 Hint

Bash arrays use parentheses without commas.

In Bash, indexed arrays are declared with parentheses and space-separated values, like arr=(red green blue). The other options use invalid syntax.

💻 Command Output

advanced

Output of Array Element Assignment

What is the output of this Bash script?

Bash Scripting

arr=()
arr[2]=orange
arr[0]=lemon
echo ${arr[@]}

A lemon

B orange lemon

C lemon orange

D orange

💡 Hint

Elements can be assigned at specific indexes; missing indexes are empty.

The array has elements at index 0 ('lemon') and index 2 ('orange'). When printing all elements with ${arr[@]}, Bash outputs them in index order, skipping empty indexes, so 'lemon orange'.

💻 Command Output

expert

Output of Indexed Array with Mixed Assignments

What is the output of this Bash script?

Bash Scripting

arr=(a b c)
arr[5]=f
echo ${#arr[@]}

A 4

B 6

C 3

D 5

💡 Hint

The length counts the number of assigned elements, not the highest index.

The array initially has 3 elements (indexes 0,1,2). Assigning arr[5]=f adds a fourth element at index 5. The total number of elements is 4, so ${#arr[@]} outputs 4.