Jq map example That example appends the string "this is great" to the "comments" array of each post in the input (where the input is an object with a field "posts" which is an array of posts). json[ { Nov 6, 2023 · The WebAssembly build of jq, as well as all the code for calling out to it is provided by BioWasm. 3, jq 1. Since I am not good at front-end, this was a substantial learning experience for me. You could also have used. you’ll learn how to use different jq filters such as prettify, filters on arrays, objects, and more complex operations involving select(), map(), and regular expressions. 26 July 2015. You can transform the data into a new format. [], the map() function leaves the array structure intact but operates on the elements. When the button is clicked, it sends an event to a listener, which makes it run jq and then update the output. The previous filter gave us an array with the id and title keys of each painting. My requirement is to filter out the JSON message if the expected node is present. Feb 23, 2020 · Tour Start here for a quick overview of the site Help Center Detailed answers to any questions you might have Jun 16, 2022 · Note the nested calls to map, i. name)[]' file Jan 27, 2015 · In addition to what others have suggested, I think that two options are worth mentioning. 4 and jq 1. Apr 13, 2021 · Lorsqu’on veut manipuler du JSON dans son terminal, la commande Jq devient indispensable Formater un Json Exemple de json “inline” jq 1. When jq encounters an assignment like 'a = b', it records the "path" taken to select a part of the input document while executing a. map() method applies a function to each item in an array or object and maps the results into a new array. It covers essential jq filters, argument usage, and techniques for efficiently processing JSON in command-line environments. Nov 17, 2023 · Through practical examples, I illustrated how jq can be effectively used to extract, modify, and restructure JSON data, making it an invaluable tool for data manipulation tasks. The map iterates over the values of the objects. I'd argue that the map function is a core building block of all data transformations. Another advanced use of jq is mapping data. Apr 21, 2025 · Conclusion. We can combine the map and has functions this way: $ jq '. There are numerous predefined functions/filters that can easily be combined using pipes to quickly create and apply complex operations and transformations. Since filters may contain spacing and other characters that hold a special meaning to your shell, it is a good practice to wrap your filter in single quotation marks. price) | add' will take an array of JSON objects as input and return the sum of their "price" fields. | length)' fruit. +1) will increment each element of an array of numbers. map(map(). A map iterates over each element in its input, and returns a new array. The first variant can be used with jq 1. json ; When using jq with files, you always pass a filter followed by the input file. Ideal for handling API data or automating tasks, the article includes practical examples and further resources for deepening your jq skills. Or else, do nothing. Filter objects based on the contents of a key. last] | @tsv' Stevie Wonder Michael Jackson $ curl cheat. jq is equally useful for updating existing JSON data. For example, jq "foo" will fail on most Unix shells because that will be the same as jq foo, which will generally fail because foo is not defined. [1])}) May 31, 2020 · The GitHub Events API as Example. No, just one. So, let’s dive in and start mastering jq! TL;DR: How Do I Use jq for JSON Processing? jq is a command-line JSON processor that allows you to parse, filter, and transform JSON data. Let’s add the primary artist for Aug 13, 2023 · jq 簡介. In our simple fruits JSON, we get true in each result item. map(f) is equivalent Oct 24, 2021 · Summary: The two functions and the way you call them differ in where the map() operation happens and what's used in the addition. See full list on baeldung. JQ Examples For example, jq "foo" will fail on most Unix shells because that will be the same as jq foo, which will generally fail because foo is not defined. com 2 days ago · jq 'map(. May 30, 2022 · Tidying up with object construction in a map. 6 it also traverses objects. item) | map({ item: first. Nov 11, 2023 · The jq command is a powerful JSON processor for querying and manipulating JSON data from the command line. json [ true, true, false ] The map function is also used to determine how many unique values there are for a given key in an array. json. id) Explanation: Rather than splitting the array with . The guide aims to aid developers, system administrators, or tech enthusiasts in effectively using `jq` to The jq Cookbook has an example of the syntax. That’s why the examples in this blog post will make use of the publicly available GitHub events API to parse some complex and nested JSON data. sheets:jq # jq # A lightweight and flexible command-line JSON processor. value) It runs the filter passed as argument to each value of the input object, collects the results and associates them with the keys of the input object and returns an object. 5 released, including new datetime, math, and regexp functions, try/catch syntax, array and object destructuring, a streaming parser, and a module system. ' seaCreatures. jq 1. type Aug 5, 2016 · A series of how to examples on using jq, a command-line JSON processor. As you can see, only the object with ‘name’ as ‘John’ and ‘age’ as 30 is returned. Basic understanding of: Feb 11, 2022 · This is more obvious if we do jq '. # Output a JSON file, in pretty-print format: jq # Output all elements from arrays # (or all key-value pairs from objects) in a JSON file: jq. I need to transform a JSON string like below to a table for output in the terminal. For example, you can group data by a certain field and then calculate Mapping. []returns each element of the array returned in the response, one at a time, which are all fed into {message: . It plays nice with UNIX pipes and offers extensive functionality for interrogating, manipulating and working with JSON file. [] | map(. Oct 27, 2022 · Here's a variation without any reduce:. Aug 8, 2015 · If one wants to avoid having to specify the mapping on the command line, then the following two variants may be of interest. 6, $. json In this example, we’re applying the has function to each item in the array and looking to see if there is a name property. For example, say we want to check the existence of the “name” key in each of the objects contained in the “characters” array. That is sort of the direction I want to go, but there's some tidying up to do, to get cleaner values for key and value. Graphviz example: Services interaction diagram Graphviz Example JQ Example: map. jq is a program described as “sed for JSON data":. I know I can get all names by. In this example, we’ll start with a JSON object that defines a command to be executed and any environment variables that should be set when the command is run: Apr 20, 2025 · Introduction. attributes[]. Following jq map select expression produces the intended outcome: As a general rule it's best to always quote (with single-quote characters) the jq program, as too many characters with special meaning to jq are also shell meta-characters. In JavaScript, map functions are attached to arrays, and if the commit data were to be mapped to return just the email address, it would look like this: Nov 15, 2023 · For example, you might learn how to use jq in combination with other command-line tools like curl to fetch and process data from APIs, or how to use jq in your programming language of choice to handle JSON data. Check it online. Your JSON content Jan 28, 2018 · jq 是个非常强大的处理 JSON 数据的命令行工具。这里记录一下最近使用 jq 所使用的一些操作，方便以后有类似需求的时候直接参考。 基本操作 jq 的命令行使用方法如下: $ jq -h jq - commandline JSON processor [version 1. Whether you're dealing with massive API responses, nested JSON structures, or cleaning datasets, jq gives you the flexibility and control you need — all from the command line. This would let me skip all the drive-by fix-my-problem issues. json with code values to be selected, it'll look like this: "123" "234" Then convert arrlstProperty into an object by keying each element with its code value, then index resulting object with keys stored in args. json | jq -r '. Use map to create a new array based on all values for the key in the array and pass this to the unique filter. sh/ cheat. Output a CSV: @csv. You can use it to slice and filter and map and transform structured data with the same ease that sed, awk, grep and friends let you May 24, 2016 · Creating simple arrays is crucial, however, for mapping our JSON into a CSV file. For practitioners and interactive learners I also recommend the great jq-play online editor where you can try jq directly in the browser. jq has reduction operators, which are very powerful but a bit tricky. This is because the outer map processes the outer array, and passes each element (each of which are also arrays - the by-year subarrays) to the function specified, which is also map , which processes (in turn) each inner array, which contain the objects. From installation to advanced usage, learn to parse, filter, and transform JSON data using jq in scripts. map(f), map_values(f) For any filter f, map(f) will run that filter for each element of the input array, and return the outputs in a new array. foo)' Group by a key - opposite to flatten: jq 'group_by(. 01 January 2015. When using the Windows command shell (cmd. Most jq examples contain trivial JSON and data structures. 6 Let’s say I want to grab all the items that are labeled. value | split (">")) | group_by (. JQ Example: map values. [0]) | to_entries | map ({key:. Oct 24, 2023 · Jq is the essential command line JSON processor for bash that allows you to slice, filter, map, and transform JSON with the same ease as traditional Unix text tools like grep, sed and awk. jq 是一個常用的指令工具，用於處理 JSON 格式的資料，輕量但功能強大，可以做到從 JSON 資料中擷取、轉換、篩選等操作，也可以簡單用於排版讓 JSON 資料更可讀。 Dec 19, 2018 · jq is a lightweight and flexible command-line JSON processorExample datafile. * Dec 11, 2022 · Using jq, how can I transform an input to a JSON object which maps the first level keys to the value of the latest nested value? For example, given the input { ";foo&quot;: { &quot;curren Sep 30, 2022 · $ jq -r 'map(select(. Dec 10, 2021 · map(select(any(. [] iterates over the values of the array. users[] | [. Similarly, map_values(f) will run that filter for each element, but it will return an object when an object is passed. This matters as in the first case, the map() in the call makes the addition in the function use the first element of each individual sub-array of the input array. Jun 12, 2021 · »jq« is a lightweight command-line JSON processor based on the concept of filters operating over a JSON stream. Prior to jQuery 1. Mapping Values. It covers how to install `jq` on various Linux distributions, basic usage examples, and advanced techniques for handling JSON data from APIs, configuration files, and more. Apr 29, 2015 · I use the following JQ command to filter out the JSON. Jan 14, 2024 · Aggregating Data: Use jq’s built-in functions like group_by, map, and reduce to perform complex data aggregation tasks. In this comprehensive 3,000+ word guide, you‘ll learn how to install jq and leverage its full power to wrangle JSON data like a pro. name}. e. commit. Here’s an example: Aug 19, 2014 · To add on top of aaiobe’s answer, here’s a few things to make it safer / more flexible to use:. Jun 22, 2024 · Pass the filter f to map such that f produces the desired JSON type (string, object, array, etc). Aug 25, 2016 · Just started out with Bash scripting and stumbled upon jq to work with JSON. [{ &quot;name&quot;: &quot;Georg. question mark for null safety; support for one level of nested arrays; jsn_ præfix for namespacing the resulting variables to avoid them overwriting your normal variables Nov 15, 2023 · We’ll delve into jq’s core functionality, explore its advanced features, and even discuss common issues and their solutions. Using . 5] Usage: jq [options] <jq filter> [file] 本文主要讲的是常用的 <jq filter> 。大部分操作可以通过 jq Jun 3, 2020 · The map function let us apply a filter to each element of a given array. type) | map({ type: first. enabled == true)) | . 5rc2 is available. Here’s a simple example of how All demos link to jqterm - an alternative interactive jq web terminal with autocomplete (and faster querying with large datasets as they're cached online in private gists). jq is one of those rare tools that can drastically improve your productivity once you master the basics. JQ Examples / map values. common | map (. json and see that the . characters | map(has("name"))' characters. Populate args. name at the end of the previous expression will first expand the array into a set of individual entries (that's what [] does) and then extract the . [1, 2])' Concatenate arrays: jq 'add' Flatten an array: jq 'flatten' Create a range of numbers: jq '[range(2;4)]' Display the type of each item: jq 'map(type)' Sort an array of basic type: jq 'sort' Sort an array of objects: jq 'sort_by(. name value from each of those. [] | jq . Jun 12, 2020 · jq: Map from nested JSON Hot Network Questions How did the Japanese Return of the Jedi movie poster end up with a green lightsaber when other versions used blue? I am using jq and want to get the "name" elements of the objects where 'location' is 'Stockholm'. jq is a lightweight and powerful command-line JSON processor. 5: If you wish to process a jQuery object — for example, $('div'). The $. May 11, 2024 · 5. It is widely used for parsing, filtering, and transforming JSON data. json | jq 'map(select(. To create a CSV table with jq we want to filter our input JSON into a series of arrays, with each array being a row of the CSV. Tip 5: Advanced JSON Object Creation Feb 1, 2023 · jq '. value | map (. Aug 24, 2021 · Maps and Selects Using JQ. The map function is a powerful function we can use to apply a filter or function to an array: $ jq 'map(has("name"))' fruits. exe) it's best to use double quotes around your jq program when given on the command-line (instead of the -f program-file option), but then double-quotes in Nov 5, 2021 · jq 'map(has("priority"))' submenu. first, . 3. "name" "Jack" "Walt" "Donald" But I can't figure out how to print only certain objects, given the value of a sub key (here: "location" : "Stockholm"). . Oct 8, 2023 · cat products. json [ true, true, true ] Conclusions It is also possible to define functions in jq, although this is is a feature whose biggest use is defining jq’s standard library (many jq functions such as map and find are in fact written in jq). group_by(. item, attributes: ( group_by(. Jan 29, 2020 · Inspired by a nice tutorial on Baeldung I’ve decided to write done some usual suspects when working with jq. Sep 20, 2022 · Use the function map_values(): map_values(. map( callback ); — use . message, name: . cat json | jq . Nov 27, 2017 · Using jq. value [0] [0], value:. jq is a fantastic command-line JSON processor. Print as CSV/TSV $ cat file. map(. Hence, I use if, elif, . foo Graphviz example: BPMN or Business process diagram Graphviz Example. When starting with an object and needing to combine the name of each element with its value, first convert it to name-value pairs using to_entries, then use map(f) to perform further mapping. Get it on the releases page. Nov 15, 2023 · In this example, we’re using the jq command to filter out objects where the ‘age’ property is greater than 25. Feb 11, 2021 · The article provides practical jq command examples for manipulating JSON data, including deleting, filtering, and indexing objects and arrays. inside the map function refers to the value part of an (object) element of the input array. This article explores the use of `jq`, a powerful command-line tool for JSON parsing and processing in Linux Bash. In that example, The . id rather than {id} avoids creating a dictionary for each selected value. map() instead. +1)' Delete 2 items: jq 'del(. status == "off"))[]. While these advanced techniques can be incredibly powerful, they also require a good understanding of both the jq ‘select’ command and the JSON data you’re working with. For instance, running the command jq 'map(. August 5, 2016; Updated September 19, 2024; jq - JSON formatting tool. It allows filtering, mapping, sorting, limiting, and other operations on JSON in a simple and efficient way. In this comprehensive guide, we will explore 15 practical examples of using jq in Linux to give you a solid […] Nov 15, 2023 · In this example, we’re first using jq ‘select’ to filter the data, then jq ‘map’ to transform the filtered data into a new array. name' file user1 user2 Tucking on []. Dec 5, 2024 · # On Ubuntu/Debian sudo apt-get install jq # On CentOS/RHEL sudo yum install jq # On macOS brew install jq # On Windows (using Chocolatey) choco install jq 2. map() supports traversing arrays and array-like objects only. status == "off"). jq - Command-line JSON processor SYNOPSIS jq [options] filter [files] jq can transform JSON in various ways, by selecting, iterating, reducing and otherwise mangling JSON documents. attributes; . jq -r 'map(select(. I have used AlpineJs to make the examples interactive. As of jQuery 1. Ask AI. price > 50))' This command filters the JSON array to include only products with prices above $50. Here's a collection of jq recipes I've collected over the last few months. committer. Nov 20, 2024 · In the example above, we created new JSON from scratch. To get a feeling of the data we’re now digesting feel free to open the events endpoint in your browser: Slurping is unnecessary here. So I reached for map to do this:. Master the use of jq for JSON processing in Linux Bash with our comprehensive guide. See installation options on the download page, and the release notes for details. The unique filter removes all duplicate values. The issues list I was looking at has many low-quality issues in it. Mapping Data with jq. Hence, this is more like a cheatsheet than a regular post. sed -n "s/. 5rc1 is available. wlms jzde ldg sgvh cdtfwu pqqplbf yqyt ynm povmcda fhwouc