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44 lines
1002 B
Markdown
44 lines
1002 B
Markdown
# Count The Number Of Things In A JSON File
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JQ is a great tool for finding out the number of things in a JSON file.
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If the top-level contents of the JSON is a list, then you can pipe it directly
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to the [`length` function](https://stedolan.github.io/jq/manual/#length).
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```bash
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// [1, 2, {"three": 4}]
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$ jq '. | length' data.json
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3
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```
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It works the same for counting the number of entries (key-value pairs) in a
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top-level JSON object.
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```bash
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// { "hello": "world", "list": [1,2,3] }
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$ jq '. | length' data.json
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2
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```
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If you are trying to get the count of a nested value, navigate to it and then
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pipe that to `length`.
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```bash
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// { "hello": "world", "list": [1,2,3] }
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$ jq '.list | length' data.json
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3
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```
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You can even count each value in a JSON object by transforming it into an array
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of the values with `[]`.
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```bash
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// { "hello": "world", "list": [1,2,3] }
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$ jq '.[] | length' data.json
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5
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3
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```
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Notice, the length of `"world"` is `5` characters and the length of `[1,2,3]`
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is `3` elements.
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