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echo '[10,20,30]' | jq 'first'Notes
`first` returns the first item from an array or stream.
jq Arrays and Objects
Deep reference for jq arrays, objects, grouping, entries, path updates, reshaping, and structural manipulation.
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Array Basics
Indexing, slicing, mapping, and searching arrays.
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echo '[10,20,30]' | jq 'last'Notes
`last` returns the final item.
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echo '[10,20,30]' | jq 'nth(1)'Notes
Useful when you prefer function form over indexing syntax.
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echo '["a","b","c"]' | jq 'index("b")'Notes
Returns the first matching index or null.
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echo '["a","b","c"]' | jq 'contains(["b"])'Notes
`contains()` works for arrays and objects.
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echo '[{"active":false},{"active":true}]' | jq 'any(.[]; .active)'Notes
`any()` is concise for boolean checks across collections.
Check whether all items match
Return true if every element satisfies a predicate.
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echo '[{"active":true},{"active":true}]' | jq 'all(.[]; .active)'Notes
`all()` verifies complete compliance across the array.
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echo '[1,2,3,4]' | jq 'reverse'Notes
Useful for display order and last-first style reports.
Object Basics
Inspect object fields and values.
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echo '{"a":1,"b":2}' | jq 'values'Notes
Use when you want to ignore keys and work with values only.
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echo '{"b":2,"a":1}' | jq 'keys_unsorted'Notes
Useful when you want original key order rather than sorted order.
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echo '{"a":1}' | jq 'type'Notes
Returns values like `object`, `array`, `string`, `number`, and `boolean`.
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echo '{"id":1,"name":"alice","email":"a@example.com","role":"admin"}' | jq '{id, name, role}'Notes
Ideal for reducing noisy API payloads.
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echo '{"first":"Alice","last":"Ng","team":"eng"}' | jq '{user: {full_name: (.first + " " + .last)}, meta: {team}}'Notes
jq object construction supports arbitrary expressions as values.
Check object contains subset
Test whether an object includes certain key-value pairs.
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echo '{"role":"admin","active":true}' | jq 'contains({role: "admin"})'Notes
Very useful for policy and config checks.
Entries and Key-Value Maps
Turn objects into entry arrays and back again.
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echo '{"a":1,"b":2}' | jq 'map_values(. * 10)'Notes
`map_values()` is concise when only object values need changing.
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echo '{"a":1,"b":3,"c":5}' | jq 'to_entries | map(select(.value >= 3)) | from_entries'Notes
A classic pattern for object filtering.
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echo '{"first_name":"Alice","last_name":"Ng"}' | jq 'to_entries | map(.key |= gsub("_"; "-")) | from_entries'Notes
Great for adapting between naming conventions.
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echo '[{"id":"u1","name":"alice"},{"id":"u2","name":"bob"}]' | jq 'map({key: .id, value: .name}) | from_entries'Notes
Convenient for building lookup tables.
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echo '[{"team":"eng","name":"a"},{"team":"eng","name":"b"},{"team":"ops","name":"c"}]' | jq 'group_by(.team) | map({key: .[0].team, value: map(.name)}) | from_entries'Notes
Excellent for reporting and reshaping lists into keyed groups.
Paths and Deep Updates
Edit or inspect nested structures by path.
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echo '{"user":{"profile":{"name":"alice"}}}' | jq 'getpath(["user","profile","name"])'Notes
Useful when paths are built dynamically.
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echo '{}' | jq 'setpath(["user","profile","name"]; "alice")'Notes
`setpath()` can create intermediate objects as needed.
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echo '{"user":{"password":"secret","token":"abc","name":"alice"}}' | jq 'delpaths([["user","password"],["user","token"]])'Notes
Very useful for scrubbing sensitive fields.
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echo '{"user":{"name":"alice","roles":["admin","dev"]}}' | jq 'paths(scalars)'Notes
Great for data profiling and flattening strategies.
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echo '{"user":{"name":"alice","roles":["admin","dev"]}}' | jq '.. | scalars'Notes
Recursive descent plus `scalars` is a good way to inspect content quickly.
Find matching nested objects
Search recursively for objects containing a field.
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echo '{"items":[{"name":"a"},{"child":{"name":"b"}}]}' | jq '.. | objects | select(has("name"))'Notes
The recursive descent operator `..` is powerful for document-wide search.
Grouping and Aggregation
Summaries, counts, and report-style reductions.
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echo '[{"status":"ok"},{"status":"fail"},{"status":"ok"}]' | jq 'group_by(.status) | map({status: .[0].status, count: length})'Notes
One of the most useful jq reporting patterns.
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echo '[{"amount":10},{"amount":15},{"amount":5}]' | jq 'map(.amount) | add'Notes
Map to the field first, then aggregate.
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echo '[{"score":80},{"score":90},{"score":100}]' | jq '(map(.score) | add) / length'Notes
Simple but common analytics pattern.
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echo '[{"name":"a","age":20},{"name":"b","age":35}]' | jq '{youngest: min_by(.age), oldest: max_by(.age)}'Notes
`min_by()` and `max_by()` are very handy for summaries.
Partition items by predicate
Split one array into matching and non-matching groups.
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echo '[{"name":"a","active":true},{"name":"b","active":false}]' | jq '{active: map(select(.active)), inactive: map(select(.active | not))}'Notes
Useful for dashboards and summary reports.
More in jq
jq CLI Recipes
Real-world jq commands for APIs, cloud tooling, DevOps output, reporting, logs, and shell scripting.
jq Filters and Transformations
Advanced jq patterns for regex, booleans, dates, math, recursive descent, filtering, and output shaping.
jq Cheat Sheet
Core jq syntax, filters, selectors, arrays, objects, variables, sorting, grouping, formatting, and shell-friendly usage.