str_replace中的函数无法正常工作

Question

Please see my code below, I am trying to put a function containing an if statement within str_replace, however, it is not injecting it into the script, thank you in advance for your help. Basically I need to replace [price] in the string with this if statement.

function price(){
    if ($_SESSION['vat'] == "ex"){ 
       echo('£'.$row_products['price'].'Ex. VAT');
    } ?>
    <?php if ($_SESSION['vat'] == "inc"){     
        $total_price = $row_products['price'] *= (1 + $VATrate / 100);
        echo('&pound;');
        printf("%.2f", $total_price); 
        echo('Inc. VAT');
    }  

}

$main_description = str_replace('[price]', price(), $row_products['description']);

Answer 1

Not tested but something along the lines of this should do the trick:

function price() {
    if ($_SESSION['vat'] == "ex"){ 
        return '£'.$row_products['price'].'Ex. VAT';
    } 

    if ($_SESSION['vat'] == "inc"){ 

        $total_price = $row_products['price'] *= (1 + $VATrate / 100);
        return sprintf("%s %.2f %s", "£", $total_price, 'Inc. VAT'); 
    }  
}