Help with a "Warning: Undefined array key" issue

PHP
1

Hello,
I am getting this warning Warning: Undefined array key when using the below code. This does return the correct value but I would like to fix the warning. The error says it is on the return line.

$locationId = '47V9D0K01JHXW';
private function getLocationMap($locationId) {
$warehouseMapArray = [];
		
		$warehouseMapArray['LSAJRJW8STWCQ'] =  1;
		$warehouseMapArray['LCF7PX9Q1ZAZ4'] =  3;
		$warehouseMapArray['L4Y9KP6KS7T30'] =  5;
		$warehouseMapArray['L9JKX4EKKK73J'] =  7;
		$warehouseMapArray['LNKAWM61JN12A'] =  8;
		$warehouseMapArray['LRWTPNRB246QV'] =  9;
		$warehouseMapArray['LTRB1Q315ESHW'] =  10;
		$warehouseMapArray['LX96YYQ39QCQS'] =  11;
		$warehouseMapArray['LQ4TKZ5WPK1WB'] =  17;
		$warehouseMapArray['47V9D0K01JHXW'] =  16;



		return $warehouseMapArray[$locationId];

}```

Any ideas is really appreciated.

Thanks
Don
2

You’d need to show us where getLocationMap() is called, and what it’s passing as the $locationId parameter. But clearly the parameter it’s passing is not one of the strings you’ve encoded in the array.

3

The location id I put just above the method is what is being passed. I actually get back a value of 16 which is correct. But I am still getting the warning.

4

Which line, specifically, is throwing the warning?

5

The return line.

6

And you’re absolutely sure that you’re only calling getLocationMap once, and only with the correct id in place?

tracknut’s correct, something is calling getLocationMap with a bad ID somewhere.

7

What is in $locationId when you display it inside the function for debugging purposes?

I make a habit of not using variable names that are the same as parameter names, where I can, to remove any kind of confusion. Seeing that you use it as the variable name in your calling code, and the parameter name inside your function, just adds a little potential for confusion to the casual viewer, even if the compiler isn’t confused.

8

Maybe you want to add a little check as you never know if the correct value will be passed.

		if(!empty($locationId) && array_key_exists($locationId,$warehouseMapArray)){
			return $warehouseMapArray[$locationId];	
		}else{ 
			return "n/a";
		}

Also is this function within a CLASS and called where $locationId = '47V9D0K01JHXW'; is not available such as outside the CLASS?

9

Null Coalesce.

10

Yes, writing as a single line would be better.

return ((!empty($locationId) && array_key_exists($locationId,$warehouseMapArray)) ? $warehouseMapArray[$locationId] : "n/a");
11

What you have shown is not calling the function so there shouldn’t be an error in the function. I guess we would all like to see how you are calling the function… Something like this with a value key inside the call?

echo getLocationMap('47V9D0K01JHXW');

How are you testing this function if you are not calling it?