PHP: check if empty line ("
")

Question

I'm using an API in order to retrieve some temperature and location values in JSON format. I'm writing the output in a plain text cachefile. However a temperature station may fail reporting the temperature value, and in that case my output will be an empty line ( ). I want to handle such case by displaying "N/A" for a non-reporting station. Here's a typical cachefile with the first station reporting temperature and location, and the second station shut down (reporting two empty lines): ``` 27.6 Napoli-Posillipo (an empty line) (an empty line) ``` I tried with: ``` $display = file($cachename); $temperature[0] = $display[0]; $location[0] = $display[1]; $temperature[1] = $display[2]; $location[1] = $display[3]; $temp_avg = (($temperature[0]+$temperature[1])/2); //average temperature if($temperature[0] = " "){ //if weather station is not reporting data $temperature[0] = "N/A"; $temp_avg = "N/A"; } if($temperature[1] = " "){ $temperature[1] = "N/A"; $temp_avg = "N/A"; } echo "

Accepted Answer

Your comparisons should look like this (note the use of two equal signs):

```
if($temperature[0] == "
"){ 
```

Your current code is assigning `"
"` to `$temperature[1]`, which evaluates true, which is why the `if` condition is executing.

If you would like to use `empty()`, which I suggest you do, change your call to `file()` to:

```
$display = file($cachename, FILE_IGNORE_NEW_LINES);
```

Adding the `FILE_IGNORE_NEW_LINES` flag will tell the function not to add newlines (`"
"`) to the end of the array elements.

PHP: check if empty line ("\n")

Solution

Problem