I am working on a college project that must use a CSV file to create the values for a table. It must have a class and it must have specific class variables (one of them I have already created for testing). Only the variables are specified as having to be part of the class but I think it would be better to pack the function inside the class (unless someone has a different opinion).

Basically, I want to use the class function to create the values for the class variables. Here is my script (refer to the comments for explanation):

    <?php
        class productRow {
            function make_table_row($i) {
                $row = 1;
                $tablerows = [];
                if (($input = fopen("input.csv", "r")) !== FALSE) {
                    while (($tabledata = fgetcsv($input, 1000, ",")) !== FALSE) {   //cycles through the rows of data creating arrays
                        if ($row == 1) {
                            $row  ;     
                            continue;       //skips the first row because it's a header row I don't want on my input
                        }
                        $tablerows[] = $tabledata;      //uses the roles to populate a multidimensional array
                        $row  ;
                    }
                    fclose($input);
                    return $tablerows[$i];      //uses the $i argument to return one of the row arrays
                }
            }
            var $itemNumber = this->make_table_row($i)[0];  //Line 118: calls make_table_row function to get the first item from the row returned
        }
        $pr1 = new productRow;
        echo $pr1->make_table_row(1);       //calls the function from within the class
    ?>

I get this error: Fatal error: Constant expression contains invalid operations in C:\xampp\htdocs\Tylersite\index.php on line 118

I know the return works because I tested it with print_r, including adding an array number as I did with that variable value to get a specific array value. So I must not be calling that function instance correctly. I've tried various things including removing the $this keyword as I wasn't sure I needed it, but the truth is I don't really know how to do it and I'm having trouble finding documentation on the correct syntax. Does anyone know what to do?

CodePudding user response：

Example using constructor function

class productRow {
    var $itemNumber = []; // default value doesn't matter as it will change in __construct

    public function __construct($i) {
        $this->itemNumber = $this->make_table_row($i)[0];
    }

    function make_table_row($i) {
        $row = 1;
        $tablerows = [];

        if (($input = fopen("input.csv", "r")) === FALSE) {
            // return early - reduces indentation
            return;
        }

        while (($tabledata = fgetcsv($input, 1000, ",")) !== FALSE) {   //cycles through the rows of data creating arrays
            if ($row == 1) {
                $row  ;
                continue;       //skips the first row because it's a header row I don't want on my input
            }
            $tablerows[] = $tabledata;      //uses the roles to populate a multidimensional array
            $row  ;
        }
        fclose($input);
        return $tablerows[$i];      //uses the $i argument to return one of the row arrays
    }
}

$pr1 = new productRow(1);
var_dump($pr1->make_table_row(1));