php - How to downgrade or install a specific version of Composer on Windows? - Stack Overflow

@echo off
color f0
:: overwrite your program name after the '=' ::
set ProgramNameHere=ProgramNameHere
goto start
:start
cd/
cd users
cd %username%
cd desktop
md %ProgramNameHere%
:: overwrite your file path on the 'DATA' ::
:: overwrite your file name on the 'file1', 'file2'...
:: overwritw your file name after the 'extracting'.
echo DATA>>C:\Users\%Username%\Desktop\%programNameHere%\file1.txt
echo extracting file 1
ping localhost>nul
echo DATA>>C:\Users\%Username%\Desktop\%programNameHere%\file2.txt
echo extracting file 2
ping localhost>nul
echo DATA>>C:\Users\%Username%\Desktop\%programNameHere%\file3.txt
echo extracting file 3
ping localhost>nul
echo DATA>>C:\Users\%Username%\Desktop\%programNameHere%\file4.txt
echo extracting file 4
ping localhost>nul
echo DATA>>C:\Users\%Username%\Desktop\%programNameHere%\file5.txt
echo extracting file 5
ping localhost>nul
echo DATA>>C:\Users\%Username%\Desktop\%programNameHere%\file6.txt
echo extracting file 6
ping localhost>nul
echo DATA>>C:\Users\%Username%\Desktop\%programNameHere%\file7.txt
echo extracting file 7
ping localhost>nul
echo DATA>>C:\Users\%Username%\Desktop\%programNameHere%\file8.txt
echo extracting file 8
ping localhost>nul
echo DATA>>C:\Users\%Username%\Desktop\%programNameHere%\file9.txt
echo extracting file 9
ping localhost>nul
echo DATA>>C:\Users\%Username%\Desktop\%programNameHere%\file10.txt
echo extracting file 10
ping localhost>nul
goto exit

:exit
exit

# Created by https://www.gitignore.io/api/laravel

### Laravel ###
vendor/
node_modules/
npm-debug.log

# Laravel 4 specific
bootstrap/compiled.php
app/storage/

# Laravel 5 & Lumen specific
public/storage
public/hot
storage/*.key
.env.*.php
.env.php
.env
Homestead.yaml
Homestead.json

# Rocketeer PHP task runner and deployment package. https://github.com/rocketeers/rocketeer
.rocketeer/

Start-Process powershell.exe -verb runAs -ArgumentList '-NoExit', '-Command', 'cd D:\folder'

composer self-update --1

<?php
function factorial ($number, $factorial = 1) {
    if ($number < 0) {
        throw new InvalidArgumentException('Number cannot be less than zero (0)');
    }
    if ($number == 0) {
        return $factorial;
    }
    else {
        return factorial($number - 1, $factorial * $number);
    }
}