> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.
# JSON PATH 2 Wild Cards
> This article provides a comprehensive guide on using the JSONPath wildcard operator for querying JSON objects and arrays effectively.
Welcome to this comprehensive guide on using the JSONPath wildcard (`*`) operator. In this lesson, you’ll discover how to apply wildcards to both JSON objects and arrays, and how to combine them for powerful queries.
JSONPath implementations can differ in syntax and features. Always test your expressions with your chosen library or tool.
***
## Wildcards in JSON Objects
Imagine you have a JSON document with two top-level entries, `car` and `bus`, each containing `color` and `price` properties:
```json theme={null}
{
"car": {
"color": "blue",
"price": "$20,000"
},
"bus": {
"color": "white",
"price": "$120,000"
}
}
```
| Task | JSONPath Expression | Output |
| ------------------- | ------------------- | ------------------------ |
| Get the car’s color | `$.car.color` | `["blue"]` |
| Get the bus’s color | `$.bus.color` | `["white"]` |
| Get **all** colors | `$.*.color` | `["blue","white"]` |
| Get **all** prices | `$.*.price` | `["$20,000","$120,000"]` |
* **Expression**: `$.*.color`\
**Result**: `["blue","white"]`
* **Expression**: `$.*.price`\
**Result**: `["$20,000","$120,000"]`
***
## Wildcards in JSON Arrays
Next, consider a simple list of wheel objects:
```json theme={null}
[
{ "model": "X345ERT", "location": "front-right" },
{ "model": "X346ERT", "location": "front-left" },
{ "model": "X347ERT", "location": "rear-right" },
{ "model": "X348ERT", "location": "rear-left" }
]
```
| Task | JSONPath Expression | Output |
| -------------------- | ------------------- | ------------------------------------------- |
| First wheel’s model | `$[0].model` | `["X345ERT"]` |
| Fourth wheel’s model | `$[3].model` | `["X348ERT"]` |
| All wheels’ models | `$[*].model` | `["X345ERT","X346ERT","X347ERT","X348ERT"]` |
* **Expression**: `$[*].model`\
**Result**: `["X345ERT","X346ERT","X347ERT","X348ERT"]`
***
## Combining Wildcards with Property Access
You can mix object wildcards and array wildcards for nested structures. Here’s a JSON object where each vehicle has a `wheels` array:
```json theme={null}
{
"car": {
"color": "blue",
"price": 20000,
"wheels": [
{ "model": "X345ERT" },
{ "model": "X346ERT" }
]
},
"bus": {
"color": "white",
"price": 120000,
"wheels": [
{ "model": "Z227KLJ" },
{ "model": "Z226KLJ" }
]
}
}
```
| Task | JSONPath Expression | Output |
| -------------------------- | ----------------------- | ------------------------------------------- |
| Car’s 1st wheel model | `$.car.wheels[0].model` | `["X345ERT"]` |
| Car’s all wheel models | `$.car.wheels[*].model` | `["X345ERT","X346ERT"]` |
| Bus’s wheel models | `$.bus.wheels[*].model` | `["Z227KLJ","Z226KLJ"]` |
| All vehicles’ wheel models | `$.*.wheels[*].model` | `["X345ERT","X346ERT","Z227KLJ","Z226KLJ"]` |
* **Expression**: `$.*.wheels[*].model`\
**Result**: `["X345ERT","X346ERT","Z227KLJ","Z226KLJ"]`
***
## Tips for Building Complex JSONPath Queries
1. Break your expression into smaller parts:
* Test one branch (e.g., `$.car.wheels[*].model`).
* Then test another (e.g., `$.bus.wheels[*].model`).
2. Once each part works, combine them with wildcards:
* Final: `$.*.wheels[*].model`
3. Use online [JSONPath evaluators](https://jsonpath.com/) to verify results interactively.
Overusing deep wildcards (`$..*`) can be inefficient on large JSON documents. Optimize your path when performance matters.
***
## Further Reading and Tools
* JSONPath Specification: [https://goessner.net/articles/JsonPath/](https://goessner.net/articles/JsonPath/)
* JSONPath Evaluator: [https://jsonpath.com/](https://jsonpath.com/)
* [Kubernetes JSONPath Guide](https://kubernetes.io/docs/reference/kubectl/jsonpath/) for real-world examples
***
Practice creating your own JSONPath expressions with wildcards to master complex data extraction scenarios!