# STARTS_WITH

Determines whether a keyword string starts with a specified prefix and returns a boolean result.

## Syntax

`STARTS_WITH(str, prefix)`

### Parameters

#### `str`

String expression. If `null`, the function returns `null`.

#### `prefix`

String expression. If `null`, the function returns `null`.

## Examples

```esql
FROM employees
| KEEP last_name
| EVAL ln_S = STARTS_WITH(last_name, "B")
```

This example checks if the `last_name` column values start with the letter "B".