PHP Functions

[lezyd]

Hello,

I am new, just learning PHP. I would like appreciate if someone could assist me with the following two questions:

(1) I will like to write a function named whatever, that contains one required and one default parameter. The function multiplies the two values.

what(50); // This function call must return the value 450
what(12,12)

Below are my codes but not working. P lease kindly assist me how to achieve the above requirement. Where I mine getting it wrong:

function what($w, $u){
$value =($w*$u);
return $value;
}
$returnValue = what(50, 9);
//echo $returnValue;

function what($what, $num=12*12){
	echo $what;
}

(2)I want to a function named changing that make use of a variable-length parameter list. I want to use the function to produce the following output:

Function received 5 arguments
Argument 0 = H
Argument 1 = e
Argument 2 = l
Argument 3 = l
Argument 4 = o

Function received 8 arguments
Argument 0 = F
Argument 1 = e
Argument 2 = e
Argument 3 = -
Argument 4 = F
Argument 5 = i
Argument 6 = -
Argument 7 = F
Argument 8 = 0

Thanks for your assistance.

[NogDog]

I don't want to do your homework for you, but I will guide you a bit: a function parameter is made optional by assigning it a default value in the function declaration:

function foo($required, $optional=null) { /* ... */ }

function foo($required, $optional=1) { /* ... */ }

Note that all required parameters must be defined before any optional parameters.

[dalecosp]

QUOTE=lezyd;11060799 I will like to write a function named whatever, that contains one required and one default parameter. The function multiplies the two values.

what(50); // This function call must return the value 450
what(12,12)

Below are my codes but not working. P lease kindly assist me how to achieve the above requirement. Where I mine getting it wrong:

function what($w, $u){
$value =($w*$u);
return $value;
}
$returnValue = what(50, 9);
//echo $returnValue;

function what($what, $num=12*12){
	echo $what;
}

[/QUOTE]Welcome to PHPBuilder 🙂

Let's see if I understand your requirements for #1.

Your function will have one required factorial argument, and one optional factorial argument, and if the optional factorial argument is not given, the second factor of the multiplication will be "9"? If so ...

//Redacted, as NogDog believes you're asking for homework help.  Perhaps you should introduce yourself more completely.

[NogDog]

And here's a tip for part of the second problem (converting a number to a character): http://php.net/manual/en/language.types.string.php#language.types.string.substr

[dalecosp]

lezyd;11060799 wrote:

Function received 8 arguments
Argument 0 = F
Argument 1 = e
Argument 2 = e
Argument 3 = -
Argument 4 = F
Argument 5 = i
Argument 6 = -
Argument 7 = F
Argument 8 = 0

Thanks for your assistance.

Incidentally, that's 9 arguments.

And as far as that goes, another RTF(riendly!)M link: http://php.net/manual/en/functions.arguments.php#functions.variable-arg-list

[lezyd]

Thank you for your reply.

I have sorted it out now.

My problem before was that, when I called the function, I got FATAL ERROR: Cannot redeclare what(previously declared)

Below are my codes and I got the values I was looking for: Please correct me if wrong:


function what($number1, $number2=NULL){

$R=$number1*$number2;

return R;

}

$c=what(50,9)// I want this function call to return 450

$d=what(12,12)

echo '$c<br/>';

echo '$d<br/>';


Secondly, please,would kindly give me clue or guildeline to produce following output, using variable-length parameter;

lezyd;11060799 wrote:

Hello,

I am new, just learning PHP. I would like appreciate if someone could assist me with the following two questions:

(1) I will like to write a function named whatever, that contains one required and one default parameter. The function multiplies the two values.

what(50); // This function call must return the value 450
what(12,12)

Below are my codes but not working. P lease kindly assist me how to achieve the above requirement. Where I mine getting it wrong:

function what($w, $u){
$value =($w*$u);
return $value;
}
$returnValue = what(50, 9);
//echo $returnValue;

function what($what, $num=12*12){
	echo $what;
}

(2)I want to a function named changing that make use of a variable-length parameter list. I want to use the function to produce the following output:

Function received 5 arguments
Argument 0 = H
Argument 1 = e
Argument 2 = l
Argument 3 = l
Argument 4 = o

Function received 8 arguments
Argument 0 = F
Argument 1 = e
Argument 2 = e
Argument 3 = -
Argument 4 = F
Argument 5 = i
Argument 6 = -
Argument 7 = F
Argument 8 = 0

Thanks for your assistance.

[lezyd]

Thank you for your reply.

I have sorted it out now.

My problem before was that, when I called the function, I got FATAL ERROR: Cannot redeclare whatever(previously declared)

Below are my codes and I got the values I was looking for: Please correct me if wrong:

1
function what($number1, $number2=NULL){
2
$R=$number1*$number2;
3
return R;
4
}
5
$c=what(50,9)// I want this function call to return 450
6
$d=what(12,12)
7
echo '$c<br/>';
8
echo '$d<br/>';

Secondly, please,would kindly give me clue or guildeline to produce following output, using variable-length parameter;

[NogDog]

At its simplest:

function what($number1, $number2=1)
{
    return $number1 * $number2;
}

To use it:

<p>The product of 50 and 9 is <?php echo what(50, 9); ?>.</p>

The thing I'll emphasize here is keeping functions narrowly focused to a specific purpose. Therefore, this function is only concerned with multiplying two numbers; it does not do any kind of output. The output in this case is left to the code that calls the function (and that code could be in another function).

[dalecosp]

In hope of enlightenment, I'll put up what I redacted earlier:

function multiply($a, $b=null) { //$b is an optional argument

if (isset($b)) {  //if $b is present we return the product of $a and $b
    return $a * $b;
}
return $a * 9;  //otherwise we return the product of $a and "nine".
}

//Usage would be as mentioned by NogDog:

echo multiply(50); //450

echo "<br>\n";  

echo multiply(12, 12);