In what situations is it necessary to use var_dump() in PHP and how does it help in debugging code?

When debugging PHP code, it is necessary to use var_dump() to display the type and value of a variable or expression. This can help identify unexpected data types or values that may be causing issues in the code. By using var_dump(), developers can quickly pinpoint the source of errors and make necessary corrections.

$variable = 5;
var_dump($variable);