Bash String Array

Bash String Array

In Bash scripting, creating and working with a string array is useful for various tasks that require managing textual data in arrays.

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Syntax

array=("value1" "value2" "value3")

The basic syntax involves using parentheses to initialize an array with string elements separated by spaces and enclosed in double quotes.

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Example Bash String Array

Let's look at some examples of how to create and work with a string array in Bash:

1. Create a String Array

This script initializes an array with string elements and prints the array.

#!/bin/bash

array=("apple" "banana" "cherry")
echo "String array: ${array[@]}"

In this script, the array variable array is initialized with the strings 'apple', 'banana', and 'cherry'. The script then prints the array.

2. Access Elements in a String Array

This script initializes a string array and prints each element by accessing them using their indices.

#!/bin/bash

array=("dog" "cat" "mouse")
echo "First element: ${array[0]}"
echo "Second element: ${array[1]}"
echo "Third element: ${array[2]}"

In this script, the array variable array is initialized with the strings 'dog', 'cat', and 'mouse'. The script then prints each element by accessing them using their indices.

3. Iterate Over a String Array

This script initializes a string array and iterates over each element to print them.

#!/bin/bash

array=("red" "green" "blue")
for element in "${array[@]}"; do
    echo "$element"
done

In this script, the array variable array is initialized with the strings 'red', 'green', and 'blue'. The for loop iterates over each element in the array and prints it.

4. Modify Elements in a String Array

This script initializes a string array, modifies an element, and prints the modified array.

#!/bin/bash

array=("one" "two" "three")
array[1]="TWO"
echo "Modified array: ${array[@]}"

In this script, the array variable array is initialized with the strings 'one', 'two', and 'three'. The second element of the array is modified to 'TWO'. The script then prints the modified array.

5. Concatenate String Arrays

This script initializes two string arrays, concatenates them, and prints the combined array.

#!/bin/bash

array1=("hello" "world")
array2=("foo" "bar")
combined_array=(${array1[@]} ${array2[@]})
echo "Combined array: ${combined_array[@]}"

In this script, the array variables array1 and array2 are initialized with strings. The elements of both arrays are concatenated into a new array, combined_array. The script then prints the combined array.

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Conclusion

Creating and working with a string array in Bash is a fundamental task for managing textual data in arrays in shell scripting. Understanding how to create, access, iterate over, modify, and concatenate string arrays can help you manage and manipulate textual data effectively in your scripts.