parse one field from an JSON array into bash array

Using jq :

$ cat json
[
  {
    "item1": "value1",
    "item2": "value2",
    "sub items": [
      {
        "subitem": "subvalue"
      }
    ]
  },
  {
    "item1": "value1_2",
    "item2": "value2_2",
    "sub items_2": [
      {
        "subitem_2": "subvalue_2"
      }
    ]
  }
]

CODE:

arr=( $(jq -r '.[].item2' json) )
printf '%s\n' "${arr[@]}"

OUTPUT:

value2
value2_2

The following is actually buggy:

# BAD: Output line of * is replaced with list of local files; can't deal with whitespace
arr=( $( curl -k "$url" | jq -r '.[].item2' ) )

---

If you have bash 4.4 or newer, a best-of-all-worlds option is available:

# BEST: Supports bash 4.4+, with failure detection and newlines in data
{ readarray -t -d '' arr && wait "$!"; } < <(
  set -o pipefail
  curl --fail -k "$url" | jq -j '.[].item2 | (., "\u0000")'
)

...whereas with bash 4.0, you can have terseness at the cost of failure detection and literal newline support:

# OK (with bash 4.0), but can't detect failure and doesn't support values with newlines
readarray -t arr < <(curl -k "$url" | jq -r '.[].item2' )

...or bash 3.x compatibility and failure detection, but without newline support:

# OK: Supports bash 3.x; no support for newlines in values, but can detect failures
IFS=$'\n' read -r -d '' -a arr < <(
  set -o pipefail
  curl --fail -k "$url" | jq -r '.[].item2' && printf '\0'
)

...or bash 3.x compatibility and newline support, but without failure detection:

# OK: Supports bash 3.x and supports newlines in values; does not detect failures
arr=( )
while IFS= read -r -d '' item; do
  arr+=( "$item" )
done < <(curl --fail -k "$url" | jq -j '.[] | (.item2, "\u0000")')

Thanks to sputnick I got to this:

arr=( $(curl -k https://localhost/api | jq -r '.[].item2') )

The JSON I have is the output from an API. All I needed to do wans remove the file argument and pipe | the output of curl to jq. Works great and saved some steps.