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---
title: "StringJoiner"
id: stringjoiner
slug: "/stringjoiner"
description: "Component to join strings from different components into a list of strings."
---
# StringJoiner
Component to join strings from different components into a list of strings.
| | |
| :------------------------------------- | :---------------------------------------------------------------------------------------------- |
| **Most common position in a pipeline** | After at least two other components to join their strings |
| **Mandatory run variables** | “strings”: Multiple strings from connected components. |
| **Output variables** | “strings”: A list of merged strings |
| **API reference** | [Joiners](/reference/joiners-api) |
| **GitHub link** | https://github.com/deepset-ai/haystack/blob/main/haystack/components/joiners/string_joiner.py |
## Overview
The `StringJoiner` component collects multiple string outputs from various pipeline components and combines them into a single list. This is useful when you need to merge several strings from different parts of a pipeline into a unified output.
## Usage
```python
from haystack.components.joiners import StringJoiner
from haystack.components.builders import PromptBuilder
from haystack.core.pipeline import Pipeline
string_1 = "What's Natural Language Processing?"
string_2 = "What is life?"
pipeline = Pipeline()
pipeline.add_component("prompt_builder_1", PromptBuilder("Builder 1: {{query}}"))
pipeline.add_component("prompt_builder_2", PromptBuilder("Builder 2: {{query}}"))
pipeline.add_component("string_joiner", StringJoiner())
pipeline.connect("prompt_builder_1.prompt", "string_joiner.strings")
pipeline.connect("prompt_builder_2.prompt", "string_joiner.strings")
result = pipeline.run(data={
"prompt_builder_1": {"query": string_1},
"prompt_builder_2": {"query": string_2}
})
print(result)
```