Change Index
Initialize or update a particular element in the array
array[10]="elevenths element" # because it's starting with 0
Append
Modify array, adding elements to the end if no subscript is specified.
array+=('fourth element' 'fifth element')
Replace the entire array with a new parameter list.
array=("${array[@]}" "fourth element" "fifth element")
Add an element at the beginning:
array=("new element" "${array[@]}")
Insert
Insert an element at a given index:
arr=(a b c d)
# insert an element at index 2
i=2
arr=("${arr[@]:0:$i}" 'new' "${arr[@]:$i}")
echo "${arr[2]}" #output: new
Delete
Delete array indexes using the unset
builtin:
arr=(a b c)
echo "${arr[@]}" # outputs: a b c
echo "${!arr[@]}" # outputs: 0 1 2
unset -v 'arr[1]'
echo "${arr[@]}" # outputs: a c
echo "${!arr[@]}" # outputs: 0 2
Merge
array3=("${array1[@]}" "${array2[@]}")
This works for sparse arrays as well.
Re-indexing an array