How to check if a variable is defined or not using Blade in Laravel?

In Blade, you can use the @if directive along with the isset function to check if a variable is defined or not. Here is an example:

@if(isset($variable))
    // Variable is defined
@else
    // Variable is not defined
@endif

You can replace $variable with the name of your variable that you want to check. If the variable is defined, the code inside the @if block will be executed. Otherwise, the code inside the @else block will be executed.

Note that you can also use the @unless directive along with the empty function to check if a variable is defined or not. Here is an example:

@unless(empty($variable))
    // Variable is defined
@else
    // Variable is not defined
@endunless

Both isset and empty are PHP functions used to check the status of a variable.