error in c++

error: use of parameter outside function body before ] token c++, 2D array in c++

c# error "The name 'ViewBag' does not exist in the current context"

Parse error: syntax error, unexpected ')' in C:\xampp\htdocs\magento\setup\src\Magento\Setup\Module.php on line 82

Fatal error: Uncaught Error: Call to undefined function mysqli_connect() in C:\Users\Joalu\Desktop\new.php:3 Stack trace: #0 {main}

51 13 c:\users\usuario\documents\destajo 1.cpp [error] 'gotoxy' was not declared in this scope

cv2.error: opencv(4.2.0) c:\projects\opencv-python\opencv\modules\imgproc\src\color.cpp:182: error: (-215:assertion failed) !_src.empty() in function 'cv::cvtcolor'

error: implicit declaration of function 'write' is invalid in c99[-werror,-wimplicit-function-declaration]write(1, &c, 1);

symfony check:requirements Fatal error: Using $this when not in object context in C:\Users\Admin\.symfony\cache\check.php on line 778 exit status 255

Uncaught Error: Call to a member function prepare() on null in C:\xampp\htdocs\facultate\CosCump\product.php:5 Stack trace: #0 {main} thrown in C:\xampp\htdocs\facultate\CosCump\product.php on line 5

Warning: Use of undefined constant vNumber - assumed 'vNumber' (this will throw an Error in a future version of PHP) in C:\xampp\htdocs\HelloWorld\vorbereitung.php on line 112