# \$1indexOfCP
<a name="indexOfCP"></a>

The `$indexOfCP` operator in Amazon DocumentDB is used to find the index, in code points (CP), of the first occurrence of a specified substring within a string expression. This can be useful when parsing and extracting content from string fields.

**Parameters**
+ `string expression`: The string to search.
+ `substring`: The substring to search for.
+ `[<start>]`: (optional) The position to start the search (zero-based index). Default is 0.

## Example (MongoDB Shell)
<a name="indexOfCP-examples"></a>

In this example, we use the `$indexOfCP` operator to find the index of the first occurrence of the hyphen character - in the Desk field of each document.

**Create sample documents**

```
db.people.insertMany([
  { "_id":1, "name":"John Doe", "Manager":"Jane Doe", "Role":"Developer", "Desk": "Düsseldorf-BVV-021"},
  { "_id":2, "name":"John Stiles", "Manager":"Jane Doe", "Role":"Manager", "Desk": "Munich-HGG-32a"},
  { "_id":3, "name":"Richard Roe", "Manager":"Jorge Souza", "Role":"Product", "Desk": "Cologne-ayu-892.50"},
  { "_id":4, "name":"Mary Major", "Manager":"Jane Doe", "Role":"Solution Architect", "Desk": "Dortmund-Hop-78"}
])
```

**Query example**

```
db.people.aggregate([
  { $project: { stateLocation: { $indexOfCP: [ "$Desk", "-"] } } }
])
```

**Output**

```
{ "_id" : 1, "stateLocation" : 10 }
{ "_id" : 2, "stateLocation" : 6 }
{ "_id" : 3, "stateLocation" : 7 }
{ "_id" : 4, "stateLocation" : 8 }
```

## Code examples
<a name="indexOfCP-code"></a>

To view a code example for using the `$indexOfCP` command, choose the tab for the language that you want to use:

------
#### [ Node.js ]

```
const { MongoClient } = require('mongodb');

async function main() {
  const client = await MongoClient.connect('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false');
  const db = client.db('test');
  const collection = db.collection('people');

  const result = await collection.aggregate([
    { $project: { stateLocation: { $indexOfCP: [ "$Desk", "-"] } } }
  ]).toArray();

  console.log(result);

  await client.close();
}

main();
```

------
#### [ Python ]

```
from pymongo import MongoClient

client = MongoClient('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false')
db = client['test']
collection = db['people']

result = list(collection.aggregate([
    { '$project': { 'stateLocation': { '$indexOfCP': [ '$Desk', '-' ] } } }
]))

print(result)

client.close()
```

------