Bash Script to Search Element in Array with Example

Use a for loop to check each element in the array and compare it with the target using if [[ "$element" == "$target" ]]; if matched, print found and exit.

Examples

Inputarray=(apple banana cherry) target=banana

OutputElement 'banana' found in the array.

Inputarray=(dog cat mouse) target=elephant

OutputElement 'elephant' not found in the array.

Inputarray=() target=any

OutputElement 'any' not found in the array.

How to Think About It

To find an element in a Bash array, you look at each item one by one and compare it to the element you want. If you find a match, you stop and say it is found. If you finish checking all items without a match, you say it is not found.

Algorithm

1

Get the array and the target element to search.

2

Loop through each element in the array.

3

Compare the current element with the target.

4

If they match, print found and stop the search.

5

If the loop ends without a match, print not found.

Code

bash

#!/bin/bash
array=(apple banana cherry)
target="banana"
found=0
for element in "${array[@]}"; do
  if [[ "$element" == "$target" ]]; then
    echo "Element '$target' found in the array."
    found=1
    break
  fi
done
if [[ $found -eq 0 ]]; then
  echo "Element '$target' not found in the array."
fi

Output

Element 'banana' found in the array.

Dry Run

Let's trace searching for 'banana' in the array (apple, banana, cherry).

1

Start loop with element 'apple'

Compare 'apple' with 'banana' → no match

2

Next element 'banana'

Compare 'banana' with 'banana' → match found, print message and stop

Element	Comparison Result
apple	no
banana	yes

Why This Works

Step 1: Loop through array elements

The for loop goes over each item in the array one by one.

Step 2: Compare each element

Inside the loop, if [[ "$element" == "$target" ]] checks if the current element matches the target.

Step 3: Stop when found

If a match is found, break stops the loop early to save time.

Step 4: Print result

If no match is found after the loop, print that the element was not found.

Alternative Approaches

Using a function to search

bash

#!/bin/bash
function contains() {
  local e
  for e in "${array[@]}"; do
    [[ "$e" == "$1" ]] && return 0
  done
  return 1
}
array=(apple banana cherry)
target="banana"
if contains "$target"; then
  echo "Element '$target' found in the array."
else
  echo "Element '$target' not found in the array."
fi

This method wraps the search in a reusable function, improving readability and reuse.

Using grep with printf

bash

#!/bin/bash
array=(apple banana cherry)
target="banana"
if printf "%s\n" "${array[@]}" | grep -qx "$target"; then
  echo "Element '$target' found in the array."
else
  echo "Element '$target' not found in the array."
fi

This uses external grep command, which can be slower but is concise and powerful.

Complexity: O(n) time, O(1) space

Time Complexity

The script checks each element once, so time grows linearly with array size.

Space Complexity

No extra space is used besides a few variables; the search is done in-place.

Which Approach is Fastest?

The loop with break is fastest for small to medium arrays; grep is slower due to process overhead.

Approach	Time	Space	Best For
For loop with break	O(n)	O(1)	Simple scripts, small arrays
Function wrapper	O(n)	O(1)	Reusable code, readability
grep with printf	O(n)	O(n)	Quick one-liners, complex patterns