array in bash scripting

An array in Bash is like a container that holds multiple pieces of data, called elements, in a single variable. 

Each element in an array has a unique index, which is like its address within the array. 

Here's a breakdown of what an array in Bash is:

Collection of Data: An array is a way to store multiple values or pieces of data in one variable.

Indexed Access: Each piece of data in an array is identified by an index number, starting from zero for the first element.

Sequential Storage: Elements in an array are stored sequentially in memory, making it easy to access them using their index.

Homogeneous: In Bash, arrays are homogeneous, meaning all elements must be of the same data type, such as strings or integers.

Variable Declaration: To create an array, you declare it using a specific syntax. For example:

fruits=("Apple" "Banana" "Orange")

Dynamic Sizing: Arrays in Bash are dynamically sized, meaning they can grow or shrink as needed to accommodate new elements.

Multiple Types: While arrays are homogeneous, Bash allows arrays to contain different types of data, but they are treated as strings.

Indexed Access: You can access elements of an array using their index. For example, ${fruits[0]} would access the first element of the fruits array.

Length: The length of an array is the number of elements it contains. You can get the length of an array using ${#array[@]}.

accessing the element by indexing:

echo "${fruits[0]}"  # Prints Apple

printing all elements of array

echo "${fruits[@]}"  # Prints all elements of the array

printing array using loops:

for fruit in "${fruits[@]}"

do

    echo "Fruit: $fruit"

done

Appending Single Element:

fruits+=("Grapes")

appending multiple elements:

fruits+=("Pineapple" "Watermelon")

removing single elements

unset fruits[1]  # Removes Banana

removing all elements

unset fruits  # Removes all elements

example: creating an array using user input:

read -p "enter elements for array" -a ar

echo "number of elements in array: ${#ar[@]}"

for a in "${ar[@]}";do

    echo $a

done

example:creating a dimensional array using user input

#!/bin/bash

read -p "enter number of rows and columns" r c

declare -A data

for a in $(seq 0  $((r-1)) );do

    for b in $(seq 0 $((c-1)) );do  

        read  val

        data[$a,$b]=val

    done

done

for a in $(seq 0  $((r-1)) );do

    for b in $(seq 0 $((c-1)) );do  

        echo "${data[$a,$b]}"

    done

done