#     
## Overview
The **`LastIndex`** **function** is used to find the index of the last instance of a substring in a `string` value.

To use this function, we must import the `strings` package in our file and access the `LastIndex` function within it, using the `.` notation (`string.LastIndex`).
  
## Syntax
The definition of the `LastIndex` function is as follows:

```
func LastIndex(str, substr string) int
```



## Parameters

The `LastIndex` function takes two arguments.

- **`str`**: This is the argument of the type `string` that we want to search inside of.

- **`substr`**: This is the `string` argument that represents the value that we want to search for inside the `str`.

## Return value
The `LastIndex` function returns the index of the last instance of the substring found inside the `str`. `-1` is returned if the substring is not found inside `str`. 

## Example code



package main

import (
	"fmt"
	"strings"
)

func main() {

	str:= "Education from Educative"

	sbstr1:=  "Ed"
	sbstr2:=  "Ad"

	check1:= strings.LastIndex(str,sbstr1)
	check2:= strings.LastIndex(str,sbstr2)

	fmt.Println("Inside \"", str,"\"")


	if check1 != -1{
	fmt.Println(sbstr1, " is present at", check1)
	} else {
	fmt.Println(sbstr1, " is not found:", )
	}

	if check2 != -1{
	fmt.Println(sbstr2, " is present at", check2 )
	} else {
	fmt.Println(sbstr2, " is not fonud:", check2)
	}

}

## Explanation
In the above code, we do the following:
- Lines 3-6: We import the `fmt` and `strings` packages.



- Line 8: We start the `main` function.


- Lines 10-13: We initialize the `string` variables `str`, `substr1`, and `substr2`.



- Lines 15-16: We run the `LastIndex` function, trying to find `substr1` and `substr2` in `str` and storing the respective values in `check1` and `check2`.


- Lines 21-25: We print the return value of `LastIndex` if `substr1` was found in `str`. Otherwise, we print `is not found`.


- Lines 27-31: We print the return value of the `LastIndex` if `substr2` was found in `str`. Otherwise, we print `is not found`.

What is the LastIndex function in Golang?

The LastIndex function in Go locates the final occurrence of a substring in a string, returning its index or -1 if absent.