Содержание

1 Accessing Function Parameters
2 A function that takes a reference for an argument
3 A Function with an Optional Argument
4 All optional arguments
5 $header
- 5.1 Capturing a return value
- 5.2 Changing argument values
6 $header

Accessing Function Parameters

   <source lang="html4strict">

<?php

 function validatelogin ($username, $password){
   $actualuser = "myusername";
   $actualpass = "mypassword";
   
   if (strcmp ($username, $actualuser) == 0 && strcmp ($password, $actualpass) == 0){
     return true;
   } else {
     return false;
   }
 }
 
 if (validatelogin ("myusername","mypassword")){
   echo "You are logged in correctly";
 } else {
   echo "You have an incorrect username and/or password";
 }

?>

 </source>

A function that takes a reference for an argument

   <source lang="html4strict">

<?php

    $my_int = 10;
    print("Before change_value(), \$my_int =" . $my_int . "
");
  
    function change_value(&$var) { 
       $var = 15; 
    }
  
    change_value($my_int);
    print("After change_value(), \$my_int = " . $my_int . "
");

?>

      </source>

A Function with an Optional Argument

   <source lang="html4strict">

<html> <body> <?php

   function headingWrap( $txt, $size=3 ) {
     print "<h$size>$txt</h$size>";
   }
   headingWrap("Book title", 1);

?> </body> </html>

 </source>

All optional arguments

   <source lang="html4strict">

<? function page_header7($color = "336699", $title = "the page", $header = "Welcome") {

   print "<html><head><title>Welcome to " . $title . "</title></head>";
   print "<body bgcolor="#" . $color . "">";

print "

$header

";

} // Acceptable ways to call this function: page_header7(); // uses all defaults page_header7("66cc99"); // uses default $title and $header page_header7("66cc99","my wonderful page"); // uses default $header page_header7("66cc99","my wonderful page","This page is great!"); // no defaults ?>

 </source>

Capturing a return value

   <source lang="html4strict">

<? function countdown($top) {

   while ($top > 0) {
       print "$top..";
       $top--;
   }
   print "boom!\n";

} $counter = 5; countdown($counter); print "Now, counter is $counter"; ?>

 </source>

Changing argument values

   <source lang="html4strict">

<? // One optional argument: it must be last function page_header5($color, $title, $header = "Welcome") {

   print "<html><head><title>Welcome to " . $title . "</title></head>";
   print "<body bgcolor="#" . $color . "">";

print "

$header

";

} // Acceptable ways to call this function: page_header5("66cc99","my wonderful page"); // uses default $header page_header5("66cc99","my wonderful page","This page is great!"); // no defaults ?>

 </source>

Creating a capitalize function with a default parameter $each

   <source lang="html4strict">

<?php function capitalize( $str, $each=TRUE ) {

 $str = strtolower($str);
 if ($each === TRUE) {
    $str = ucwords ($str);
 } else {
    $str = strtoupper($str);
 }
 echo ("$str 
");

} capitalize("hEllo WoRld!"); capitalize("hEllo WoRld!",FALSE); ?>

 </source>

Creating Functions That Take a Variable Number of Arguments

   <source lang="html4strict">

<?php

 function addanything (){
   $total = 0;
   $args = func_get_args ();
   for ($i = 0; $i < count ($args); $i++){
     if (is_int ($args[$i])){
       $total += $args[$i];
     }
   }
   return $total;
 }
 echo addanything (1,5,7,8,11) . "
";

?>

 </source>

Declaring a Function That Requires Arguments

   <source lang="html4strict">

<html> <head> <title>Declaring a Function That Requires Arguments</title> </head> <body> <?php function printBR( $txt ) {

    print ("$txt
\n");

} printBR("This is a line"); printBR("This is a new line"); printBR("This is yet another line"); ?> </body> </html>

      </source>

Declaring a Function with Arguments

   <source lang="html4strict">

 <?php
 function printcheck ($sometext){
     print ("$sometext \n");
 }
 printcheck ("A.");
 printcheck ("AA.");
 printcheck ("AAA!");
 ?>
          
      </source>

Default Parameters

   <source lang="html4strict">

function doHello($Name = "Paul") {

           return "Hello $Name!\n";
   }
   doHello( );
   doHello("Paul");
   doHello("Andrew");
 
 </source>

Define whether a variable is passed by value or reference

   <source lang="html4strict">

<?php function f1($a) {

 $a += 4;

} function f2(&$a) {

 $a += 10;

} $b = 5; f1(&$b); f2($b); echo "\$b = $b\n"; ?>

 </source>

Defining and Calling a two-argument function,

   <source lang="html4strict">

<? function page_header4($color, $title) {

   print "<html><head><title>Welcome to " . $title . "</title></head>";
   print "<body bgcolor="#" . $color . "">";

} ?> //Multiple optional arguments page_header4("66cc66","my homepage");

 </source>

Function Arguments

   <source lang="html4strict">

<?php

 function addup( $a = 32, $b = 32, $c = 32)
 {
   $total = $a + $b + $c;
   echo("$a + $b + $c = $total");
 }

?>

<html>

<head>
 <title>Function Arguments</title>
</head>
<body>

<?php addup(8, 16, 24); ?>

<?php addup(8, 16); ?>

</body>

</html>

 </source>

Functions and References

   <source lang="html4strict">

<?php

    $val1 = "";
    $val2 = "";
  
    function return_multi_value(&$value1, &$value2)
    {
         $value1 = "This is the first value";
         $value2 = "This is the second value";
    }
  
    return_multi_value($val1, $val2);
    print("$val1
$val2
");

?>

      </source>

Function with an Optional Argument

   <source lang="html4strict">

<html> <head> <title>Function with an Optional Argument</title> </head> <body> <?php function fontWrap( $txt, $size=3 ){

  print "$txt";

} fontWrap("call 1
",5); fontWrap("call 2
"); fontWrap("call 3
"); fontWrap("call 4
"); ?> </body> </html>

      </source>

Function with default parameters

   <source lang="html4strict">
 <HTML>
 <HEAD>
 <TITLE> Printing text on a Web Page</TITLE>
 </HEAD>
 <BODY>
 <?php
 function textonweb ($content, $fontsize=3){
    echo "$content";
 }
 textonweb ("A 
", 7);
 textonweb ("AA.
");
 textonweb ("AAA. 
");
 textonweb ("AAAA! 
");
 ?>
 </BODY>
 </HTML>
          
      </source>

Function with two parameters

   <source lang="html4strict">

<? function addNums( $num1, $num2 ) {

   $result = $num1 + $num2;

$ret = ""; $ret .= ""; $ret .= ""; $ret .= ""; $ret .= "

number 1:	$num1
number 2:	$num2
result:	$result

";

   return $ret;

} print addNums (49, 60); ?>

 </source>

Making arguments be passed by reference

   <source lang="html4strict">

<? function add_some_extra(&$string) {

   $string .= "and something extra.";

} $str = "This is a string, "; add_some_extra($str); echo $str; function foo ($bar) { $bar .= " and something extra."; } $str = "This is a string, "; foo ($str); echo $str; foo (&$str); echo $str; ?>

 </source>

Passing an Argument to a Function by Value

   <source lang="html4strict">

<html> <head> <title>Passing an Argument to a Function by Value</title> </head> <body> <?php function addFive( $num ) {

    $num += 5;

} $orignum = 20; addFive( $orignum ); print( $orignum ); ?> </body> </html>

      </source>

Passing By Reference

   <source lang="html4strict">

function square1($number) {

           return $number * $number;
   }
   $val = square1($val);
   function square2(&$number) {
           $number = $number * $number;
   }
   square2($val);
 
 </source>

Passing Variables as a Reference to the Argument of a Function

   <source lang="html4strict">

<?php

 function somefunct ($somearg){
   $somearg += 3;
 }
 $othernum = 12;
 somefunct ($othernum);
 echo "$othernum","\n";
 
 somefunct (&$othernum);
 echo "$othernum","\n";

?>

      </source>

Using a Function Call to Pass an Argument to a Function by Reference

   <source lang="html4strict">

<html> <head> <title>Using a Function Call to Pass an Argument to a Function by Reference</title> </head> <body> <?php function addFive( $num ){

    $num += 5;

} $orignum = 20; addFive( &$orignum ); print( $orignum ); ?> </body> </html>

      </source>

Using Optional Parameters

   <source lang="html4strict">

<?php $access = array("a", "c", "h", "r", "r"); $admin = array("e", "q"); function check_access($username, $adminonly = false) {

   global $access, $admin;
   if (in_array($username, $admin)) {
       return true;
   }
   if (!($adminonly) && in_array($username, $access)) {
       return true;
   }
   return false;

} echo check_access("r") ? "is" : "is NOT" ," allowed.</p>"; echo check_access("q") ? "is" : "is NOT" ," allowed.</p>"; echo check_access("r", true) ? "is" : "is NOT" ," an admin.</p>"; echo check_access("q", true) ? "is" : "is NOT" ," an admin.</p>"; ?>

 </source>

PHP/Functions/Parameters

Содержание

Accessing Function Parameters

A function that takes a reference for an argument

A Function with an Optional Argument

All optional arguments

$header

Capturing a return value

Changing argument values

$header

Creating a capitalize function with a default parameter $each

Creating Functions That Take a Variable Number of Arguments

Declaring a Function That Requires Arguments

Declaring a Function with Arguments

Default Parameters

Define whether a variable is passed by value or reference

Defining and Calling a two-argument function,

Function Arguments

<?php addup(8, 16, 24); ?>

<?php addup(8, 16); ?>

Functions and References

Function with an Optional Argument

Function with default parameters

Function with two parameters

Making arguments be passed by reference

Passing an Argument to a Function by Value

Passing By Reference

Passing Variables as a Reference to the Argument of a Function

Using a Function Call to Pass an Argument to a Function by Reference

Using Optional Parameters

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