Bash Array

Bash Array – An array is a collection of elements. Unlike in many other programming languages, in bash, an array is not a collection of similar elements. Since bash does not discriminate string from a number, an array can contain a mix of strings and numbers.

Bash Array

Bash Array Tutorials

The following tutorials deal with the individual concepts of an array in details with well explained examples.

Basics

Looping Scenarios

Find / Check

Modifications

Bash Array Declaration

To declare a variable as a Bash Array, use the keyword declare and the syntax is

declare -a arrayname

Example

In the following script, we declare an array with name fruits.

declare -a fruits

Bash Array Initialization

To initialize a Bash Array, use assignment operator =, and enclose all the elements inside braces (). The syntax to initialize a bash array is

arrayname=(element1 element2 element3)

Example

In the following script, we initialize an array fruits with three elements.

fruits=("apple" "banana" "cherry")

Access elements of Bash Array

We can access elements of a Bash Array using the index.

echo ${ARRAY_NAME[2]}

Example

In the following script, we access elements of array fruits with indices.

fruits=("apple" "banana" "cherry")
echo ${fruits[0]}
echo ${fruits[1]}

Print Bash Array with Indices and Details

To print all the elements of a bash array with all the index and details use declare with option p.

declare -p arrayname

Example

fruits=("apple" "banana" "cherry")
declare -p fruits

Output

declare -a fruits='([0]="apple" [1]="banana" [2]="cherry")'

Loop through Elements of Array using For Loop

We can loop through elements of array using for loop, as shown in the following example.

Example

fruits=("apple" "banana" "cherry")
for element in "${fruits[@]}";
do
    echo $element
done

Output

apple
banana
cherry

Conclusion

Concluding this Bash Tutorial, we have learnt how to declare, initialize and access Bash Arrays, with the help of examples.