FAQ: Introduction to PHP Functions - Default Parameters

This community-built FAQ covers the “Default Parameters” exercise from the lesson “Introduction to PHP Functions”.

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FAQs on the exercise Default Parameters

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What is the error, the result is correct.

function calculateTip($num1, $num2 = "20"){
   echo $num1 + ($num2*$num1)/100;
echo calculateTip(100, 25) . "\n";
echo calculateTip(100) . "\n";
echo calculateTip(65, 15);

$num2 = “20” not correct
$num2 = 20 correct

the result is correct, what is the issue?

<?php function calculateTip($totalbill,$tip=20) {echo $totalbill + ($totalbill*($tip/100));}; echo calculateTip(100); echo calculateTip(500,30);

You need to return the result, not echo it.

te pide retornar no imprimir, ese echo es return

function calculateTip($totalbill,$tip=20)


return $totalbill + ($totalbill*($tip/100));


echo calculateTip(100, 25) ."\n";

echo calculateTip(100) ."\n";

echo calculateTip(65, 15);

Hi, Is this wrong or just different? The results seem to be correct.

function calculateTip($meal,$tip=20)
return $meal + ($meal * $tip /100);
echo calculateTip(25,10);


Works as expected, are you getting an error?

Hi, thanks for replying. It just shows as different to the expected solution, doesn’t say it’s wrong, but neither confirms it is correct, like it normally does.

Hi everyone, first post here- I can’t understand what’s wrong with my code:

function calculateTip($total, $tip = 20)

  return $total + (($tip/$total) * 100);


I receive the message: If a second argument is provided, your function should use that to calculate the tip and return the previous total plus the tip amount.

When I actually use the function for calculations, it seems correct, so what am I doing wrong?