I want to show the old input in input value. If there isn\'t old input, than show other variable:
value=\"{{ old(\'salary_\' . $employee->id) or \'Default\' }         
        
or is a comparison operator in PHP, so your code is evaluating to true, or 1. What you want is a ternary if statement.
As mentioned, or can be used in blade as shorthand for a ternary if statement.
But you can (and should) just pass the default value as the second argument to the function, like so:
value="{{ old('salary_' . $employee->id, 'Default') }}"