Often in Bash you may want to join all of the elements from an array into a single string with a specific delimiter.
You can use the following syntax to do so:
my_string=$(IFS=, ; echo "${my_array[*]}")
This particular example will join all of the elements from the array named my_array into a single string named my_string, in which each element is separated using a comma.
Note that we use the IFS (“internal field separator”) command to specify the delimiter that should be used when joining the elements together into a string.
The following example shows how to use this syntax in practice.
Example: How to Join Elements from Array into Delimited String in Bash
Suppose that create a variable named my_array in Bash that contains the names of various basketball teams:
my_array=(Mavs Hawks Spurs Kings Celtics)
Suppose that we would like to join all of the elements of this array into a single string in which each element is separated by a comma.
We can use the following syntax to do so:
my_string=$(IFS=, ; echo "${my_array[*]}")
echo $my_string
The following screenshot shows how to use this syntax in practice:

When we use the echo statement to view the new string variable we can see that it contains all of the elements from the array, joined together using a comma as a separator.
Note that you can specify any separator that you’d like following the IFS command.
For example, you could use the following syntax to join together all of the elements into a single string using a dash as a separator instead:
my_string=$(IFS=- ; echo "${my_array[*]}")
echo $my_string
The following screenshot shows how to use this syntax in practice:

Notice that the string variable now contains all of the elements from the array joined together, using a dash as a separator.
Feel free to use similar syntax to join together the elements from your own array into a single string.
Related Tutorials
The following tutorials explain how to perform other common tasks in Bash:
Bash: How to Extract First Number from a String
Bash: How to Split a String into Multiple Variables
Bash: How to Count Number of Words in String
Bash: How to Count Number of Characters in String
