Return to Answer

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' ) )

Instead, use:

# OKAY (with bash 4.x+), but can't detect failure and doesn't support values with newlines
readarray -t arr < <(curl -k "$url" | jq -r '.[].item2' )

...or, even better, one of the following:

# BETTER: 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...

# BETTER: 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")')

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")')

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 -cr '.[].item2' ) )

Instead, use:

# OKAY (with bash 4.x+), but can't detect failure and doesn't support values with newlines
readarray -t arr < <(curl -k "$url" | jq -r '.[].item2' )

...or, even better, one of the following:

# BETTER: 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...

# BETTER: 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")')

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' ) )

Instead, use:

# OKAY (with bash 4.x+), but can't detect failure and doesn't support values with newlines
readarray -t arr < <(curl -k "$url" | jq -r '.[].item2' )

...or, even better, one of the following:

# BETTER: 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...

# BETTER: 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")')

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 -cr '.[].item2' ) )

Instead, use:

# GOOD (with bash 4.x+), but can't detect failure
readarray -t arr < <(curl -k "$url" | jq -cr '.[].item2' )

...or, even better...

# GOOD (with bash 3.x+), *and* has nonzero status if curl or jq fails
IFS=$'\n' read -r -d '' -a arr \
  < <(set -o pipefail; curl --fail -k "$url" | jq -cr '.[].item2' && printf '\0')

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 -cr '.[].item2' ) )

Instead, use:

# OKAY (with bash 4.x+), but can't detect failure and doesn't support values with newlines
readarray -t arr < <(curl -k "$url" | jq -r '.[].item2' )

...or, even better, one of the following:

# BETTER: 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...

# BETTER: 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")')