JSON.ARRINDEX

Syntax

  1. JSON.ARRINDEX key path value [start [stop]]

Time complexity: O(N) when path is evaluated to a single value where N is the size of the array, O(N) when path is evaluated to multiple values, where N is the size of the key

ACL categories: @json

Search for the first occurrence of a JSON value in an array

Examples

Required arguments

key

is key to parse.

value

is value to find its index in one or more arrays.

JSON.ARRINDEX - 图1About using strings with JSON commands

To specify a string as an array value to index, wrap the quoted string with an additional set of single quotes. Example: '"silver"'. For more detailed use, see Examples.

Optional arguments

start

is inclusive start value to specify in a slice of the array to search. Default is 0.

stop

is exclusive stop value to specify in a slice of the array to search, including the last element. Default is 0. Negative values are interpreted as starting from the end.

JSON.ARRINDEX - 图2About out-of-range indexes

Out-of-range indexes round to the array’s start and end. An inverse index range (such as the range from 1 to 0) returns unfound or -1.

Return value

JSON.ARRINDEX returns an array of integer replies for each path, the first position in the array of each JSON value that matches the path, -1 if unfound in the array, or nil, if the matching JSON value is not an array. For more information about replies, see Redis serialization protocol specification.

Examples

Find the specific place of a color in a list of product colors

Create a document for noise-cancelling headphones in black and silver colors.

  1. dragonfly> JSON.SET item:1 $ '{"name":"Noise-cancelling Bluetooth headphones","description":"Wireless Bluetooth headphones with noise-cancelling technology","connection":{"wireless":true,"type":"Bluetooth"},"price":99.98,"stock":25,"colors":["black","silver"]}'
  2. OK

Add color blue to the end of the colors array. JSON.ARRAPEND returns the array’s new size.

  1. dragonfly> JSON.ARRAPPEND item:1 $.colors '"blue"'
  2. 1) (integer) 3

Return the new length of the colors array.

  1. JSON.GET item:1
  2. "{\"name\":\"Noise-cancelling Bluetooth headphones\",\"description\":\"Wireless Bluetooth headphones with noise-cancelling technology\",\"connection\":{\"wireless\":true,\"type\":\"Bluetooth\"},\"price\":99.98,\"stock\":25,\"colors\":[\"black\",\"silver\",\"blue\"]}"

Get the list of colors for the product.

  1. dragonfly> JSON.GET item:1 '$.colors[*]'
  2. "[\"black\",\"silver\",\"blue\"]"

Insert two more colors after the second color. You now have five colors.

  1. dragonfly> JSON.ARRINSERT item:1 $.colors 2 '"yellow"' '"gold"'
  2. 1) (integer) 5

Get the updated list of colors.

  1. dragonfly> JSON.GET item:1 $.colors
  2. "[[\"black\",\"silver\",\"yellow\",\"gold\",\"blue\"]]"

Find the place where color silver is located.

  1. dragonfly> JSON.ARRINDEX item:1 $..colors '"silver"'
  2. 1) (integer) 1

See also

JSON.ARRAPPEND | JSON.ARRINSERT