---
title: "substring"
description: "Will return the portion of the string from the startIndex to the endIndex, or end of the string if endIndex is not specified"
---

# substring

> Will return the portion of the string from the startIndex to the endIndex, or end of the string if endIndex is not specified

**This function is used by Ignition's Expression language.**

## Description
Substring will return the portion of the string from the startIndex to the endIndex, or end of the string if endIndex is not specified. All indexes start at 0, so in the string "Test", "s" is at index 2. Indexes outside of the range of the string throw a StringIndexOutOfBoundsException.

## Syntax
`substring(string, startIndex[, endIndex])`

### Parameters

| Type | Parameter | Description |
|---|---|---|
| String | `string` | The starting string. |
| Integer | `startIndex` | The index to start the substring at. |
| Integer | `endIndex` | Optional. The end index of the substring. |

### Results
**String** - The substring from the start to end indexes of the specified string.

## Examples
```python title="Code Snippet"
substring("unhappy", 2) //returns "happy"
```
```python title="Code Snippet"
substring("hamburger", 4, 8) //Returns "urge" - note 8 is the index of "r", but the end index is exclusive.
```