Check day and do something if it is a workday or weekend

I want to to do something when the day is a workday, and do something else when it is a weekend.

But my function echoes “yes” every time, and I don’t get it.

var_dump($dag_datumloop);// Saturday is value
if ($dag_datumloop == "Monday" or "Tuesday" or "Wednesday" or "Thursday" or 
"Friday"){
       echo "yes"; 
}else if($dag_datumloop == "Saturday" or "Sunday"){
       echo "no";
}

Answer

Your current check is only checking to see if $dag_datumloop is equal to Monday. The rest are being evaluated on their own.

if (($dag_datumloop == "Monday") or ("Tuesday") or ("Wednesday") or ("Thursday") or ("Friday")){

The other days would be evaluated as true because they’re all string values. The easiest way to check it would to be use in_array instead of doing $dag_datumloop == for each one:

if(in_array($dag_datumloop, ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday']))