How to Iterate Array in Bash: Simple Loop Examples

In Bash, you can iterate over an array using a for loop with the syntax for element in "${array[@]}"; do ... done. This loops through each item in the array, allowing you to process them one by one.

Syntax

The basic syntax to iterate over an array in Bash is:

• for element in "${array[@]}"; do - starts the loop, where element takes each value.
• commands - commands to run for each element.
• done - ends the loop.

${array[@]} expands to all elements of the array.

bash

for element in "${array[@]}"; do
  echo "$element"
done

Example

This example shows how to create an array and print each element using a for loop.

bash

# Define an array
fruits=(apple banana cherry)

# Loop through the array
for fruit in "${fruits[@]}"; do
  echo "Fruit: $fruit"
done

Output

Fruit: apple
Fruit: banana
Fruit: cherry

Common Pitfalls

Common mistakes when iterating arrays in Bash include:

• Using ${array[*]} without quotes, which concatenates all elements into one string.
• Not quoting "${array[@]}", causing word splitting and incorrect iteration.
• Confusing array indices with values.

Always quote "${array[@]}" to preserve each element as a separate word.

bash

# Wrong way (no quotes, all elements combined):
fruits=(apple banana cherry)
for fruit in ${fruits[*]}; do
  echo "$fruit"
done

# Right way (quotes preserve elements):
for fruit in "${fruits[@]}"; do
  echo "$fruit"
done

Output

apple
banana
cherry
Fruit: apple
Fruit: banana
Fruit: cherry

Quick Reference

Concept	Syntax	Description
Array definition	array=(val1 val2 val3)	Creates an array with elements.
Iterate array	for item in "${array[@]}"; do ... done	Loops over each element.
Access element	${array[index]}	Gets element at position index.
Array length	${#array[@]}	Number of elements in array.

Key Takeaways

Use for loops with "${array[@]}" to iterate each element safely.

Always quote "${array[@]}" to avoid word splitting issues.

Define arrays with parentheses and space-separated values.

Access elements by index using ${array[index]}.

Check array length with ${#array[@]} when needed.