Difference between revisions of "PHP 2"

From Ilianko
 
(18 intermediate revisions by the same user not shown)
Line 7: Line 7:
 
  $myZeroString = '';
 
  $myZeroString = '';
  
 +
var_dump($myVar);
  
=== type casting ===
+
  http://php.net/manual/en/types.comparisons.php
 
 
Да се внимава със загубата на информация
 
   
 
 
 
 
$myVar = 1.1;
 
$myVar = (int) $myVar;
 
$myVar = (string) $myVar;
 
$myVar = (bool) $myVar;
 
 
 
var_dump($myVar);
 
  
 
  //var_dump(  $myZero = $myVar );
 
  //var_dump(  $myZero = $myVar );
Line 41: Line 31:
 
  //var_dump(  $myString === $myZero );
 
  //var_dump(  $myString === $myZero );
  
 +
Да се внимава със загубата на информация
  
<table class="doctable table">
+
$myVar = 1.1;
  <caption><strong>Comparisons of <var class="varname"><var class="varname">$x</var></var> with PHP functions</strong></caption>
+
$myVar = (int) $myVar;
 
+
$myVar = (string) $myVar;
    <thead>
+
$myVar = (bool) $myVar;
    <tr>
 
      <th>Expression</th>
 
      <th> <span class="function"><a href="function.gettype.php" class="function">gettype()</a></span></th>
 
      <th> <span class="function"><a href="function.empty.php" class="function">empty()</a></span></th>
 
      <th> <span class="function"><a href="function.is-null.php" class="function">is_null()</a></span></th>
 
      <th> <span class="function"><a href="function.isset.php" class="function">isset()</a></span></th>
 
      <th><span class="type"><a href="language.types.boolean.php" class="type boolean">boolean</a></span> : <em>if($x)</em></th>
 
    </tr>
 
 
 
    </thead>
 
 
 
    <tbody class="tbody">
 
    <tr>
 
      <td><em>$x = &quot;&quot;;</em></td>
 
      <td><span class="type"><a href="language.types.string.php" class="type string">string</a></span></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>$x = null;</em></td>
 
      <td><span class="type"><a href="language.types.null.php" class="type NULL">NULL</a></span></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>var $x;</em></td>
 
      <td><span class="type"><a href="language.types.null.php" class="type NULL">NULL</a></span></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><var class="varname"><var class="varname">$x</var></var> is undefined</td>
 
      <td><span class="type"><a href="language.types.null.php" class="type NULL">NULL</a></span></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>$x = array();</em></td>
 
      <td><span class="type"><a href="language.types.array.php" class="type array">array</a></span></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>$x = false;</em></td>
 
      <td><span class="type"><a href="language.types.boolean.php" class="type boolean">boolean</a></span></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>$x = true;</em></td>
 
      <td><span class="type"><a href="language.types.boolean.php" class="type boolean">boolean</a></span></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>$x = 1;</em></td>
 
      <td><span class="type"><a href="language.types.integer.php" class="type integer">integer</a></span></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>$x = 42;</em></td>
 
      <td><span class="type"><a href="language.types.integer.php" class="type integer">integer</a></span></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>$x = 0;</em></td>
 
      <td><span class="type"><a href="language.types.integer.php" class="type integer">integer</a></span></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>$x = -1;</em></td>
 
      <td><span class="type"><a href="language.types.integer.php" class="type integer">integer</a></span></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>$x = &quot;1&quot;;</em></td>
 
      <td><span class="type"><a href="language.types.string.php" class="type string">string</a></span></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>$x = &quot;0&quot;;</em></td>
 
      <td><span class="type"><a href="language.types.string.php" class="type string">string</a></span></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>$x = &quot;-1&quot;;</em></td>
 
      <td><span class="type"><a href="language.types.string.php" class="type string">string</a></span></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>$x = &quot;php&quot;;</em></td>
 
      <td><span class="type"><a href="language.types.string.php" class="type string">string</a></span></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>$x = &quot;true&quot;;</em></td>
 
      <td><span class="type"><a href="language.types.string.php" class="type string">string</a></span></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
    </tr>
 
 
 
    <tr>
 
      <td><em>$x = &quot;false&quot;;</em></td>
 
      <td><span class="type"><a href="language.types.string.php" class="type string">string</a></span></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>FALSE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
      <td><strong><code>TRUE</code></strong></td>
 
    </tr>
 
 
 
    </tbody>
 
 
 
  </table>
 
 
 
  
 
== if ==
 
== if ==
Line 225: Line 47:
 
   echo 'You are logged';
 
   echo 'You are logged';
 
  }
 
  }
 
+
 
  echo 'Click Next';
 
  echo 'Click Next';
  
Line 231: Line 53:
  
 
  $myVar = 'Ivan';
 
  $myVar = 'Ivan';
 
+
 
  if($myVar == 'logged'){
 
  if($myVar == 'logged'){
 
   echo 'You are logged';
 
   echo 'You are logged';
Line 238: Line 60:
 
   echo 'Please login';
 
   echo 'Please login';
 
  }
 
  }
 
+
 
  echo 'Click Next';
 
  echo 'Click Next';
  
Line 251: Line 73:
 
  else
 
  else
 
   $text = 'Please register
 
   $text = 'Please register
 
+
 
  echo $text.' Click Next';
 
  echo $text.' Click Next';
  
Line 258: Line 80:
 
  $text = ($myVar == 'logged') ? 'You are logged' : 'Please login';
 
  $text = ($myVar == 'logged') ? 'You are logged' : 'Please login';
 
  echo $text.' Click Next';
 
  echo $text.' Click Next';
 
  
 
== for ==
 
== for ==
 +
 +
for ($i = 0; $i < 10; $i++){}
  
 
=== for ===
 
=== for ===
 +
 +
for ($i = 0; $i < 10; $i++){
 +
  echo $i.'&lt;br />';
 +
}
 +
 +
echo $i.'END';
 +
 +
for ($i = 0; $i < 10; ++$i){
 +
  echo $i.'&lt;br />';
 +
}
 +
 +
echo $i.'END';
 +
 +
$i = 0;
 +
for (; $i < 10; $i++){
 +
  echo $i.'&lt;br />';
 +
}
 +
 +
echo $i.'END';
 +
 +
$i = 0;
 +
for (;$i < 10;){
 +
  $even[] = $i;
 +
  $i = $i+2;
 +
}
 +
 +
echo '&lt;pre>';
 +
print_r($even);
 +
echo '&lt;/pre>';
 +
 +
$i = 1; $max = 10;
 +
for (;;){
 +
  $odd[] = $i;
 +
  if( $i > $max){
 +
    break;
 +
  }     
 +
  $i = $i+2;
 +
}
 +
 +
echo '&lt;pre>';
 +
print_r($odd);
 +
echo '&lt;/pre>';
  
 
=== foreach ===
 
=== foreach ===
 +
 +
$even = array( 0, 2, 4, 6, 8);
 +
 +
foreach($myVar as $value)
 +
{
 +
  echo $value.'&lt;br />';
 +
}
  
 +
$even = array( 0, 2, 4, 6, 8);
 +
 +
foreach($myVar as $value)
 +
{
 +
  if( $value == 4 ){
 +
    continue;
 +
  }
 +
  echo $value.'&lt;br />';
 +
}
 +
 +
$myNames['first'] = 'Ivan';
 +
$myNames['second'] = 'Ivanov';
 +
$myNames['last'] = 'Todorov';
 +
 +
foreach($myNames as $key => $value){
 +
  echo $key.': '.$value.'<br />';
 +
}
  
 
== while ==
 
== while ==
 +
 +
Контролираме условието
 +
 +
$i = 0;
 +
while( $i < 10 )
 +
{
 +
  echo $i.'<br />';
 +
  $i++;
 +
}
  
 
== switch ==
 
== switch ==

Latest revision as of 11:03, 20 October 2013

Условни оператори

$myVar = 1;
$myZero = 0;
$myString = 'ilian';
$myZeroString = ;
var_dump($myVar);
http://php.net/manual/en/types.comparisons.php
//var_dump(  $myZero = $myVar );
//var_dump(  $myVar = $myZero );
//var_dump(  $myZero = $myString );

//var_dump(  $myZero == $myVar );
//var_dump(  $myZero == $myString ); 
//var_dump(  $my == $myZeroString ); 

//var_dump(  $myVar === $myString ); 
//var_dump(  $myVar === $myZeroString ); 
//var_dump(  $myVar == $myString );
//var_dump(  $myZeroString == $myVar );
//var_dump(  $myZeroString == $myZero );
//var_dump(  $myZeroString == $myString );

//var_dump(  $myZeroString === $myString );
//var_dump(  $myZeroString === $myVar );
//var_dump(  $myZeroString === $myZero );
//var_dump(  $myString === $myZero );

Да се внимава със загубата на информация

$myVar = 1.1;
$myVar = (int) $myVar;
$myVar = (string) $myVar;
$myVar = (bool) $myVar;

if

if

$myVar = 'Ivan';

if($myVar == 'logged'){
  echo 'You are logged';
}

echo 'Click Next';

if else

$myVar = 'Ivan';

if($myVar == 'logged'){
  echo 'You are logged';
}
else {
  echo 'Please login';
}

echo 'Click Next';

if elseif else

if($myVar == 'logged'){
  $text = 'You are logged';
}
elseif($myVar == 'guest') {
  $text = 'Please choose name';
}
else
  $text = 'Please register

echo $text.' Click Next';

() ? :

$text = ($myVar == 'logged') ? 'You are logged' : 'Please login';
echo $text.' Click Next';

for

for ($i = 0; $i < 10; $i++){}

for

for ($i = 0; $i < 10; $i++){
  echo $i.'<br />';
}

echo $i.'END';
for ($i = 0; $i < 10; ++$i){
  echo $i.'<br />';
}

echo $i.'END';
$i = 0;
for (; $i < 10; $i++){
  echo $i.'<br />';
}

echo $i.'END';
$i = 0;
for (;$i < 10;){
  $even[] = $i;
  $i = $i+2;
}

echo '<pre>'; 
print_r($even);
echo '</pre>';
$i = 1; $max = 10;
for (;;){
  $odd[] = $i;
  if( $i > $max){
    break;
  }      
  $i = $i+2;
}

echo '<pre>'; 
print_r($odd);
echo '</pre>';

foreach

$even = array( 0, 2, 4, 6, 8);

foreach($myVar as $value)
{
  echo $value.'<br />';
}
$even = array( 0, 2, 4, 6, 8);

foreach($myVar as $value)
{
  if( $value == 4 ){
    continue;
  }
  echo $value.'<br />';
}
$myNames['first'] = 'Ivan';
$myNames['second'] = 'Ivanov';
$myNames['last'] = 'Todorov';

foreach($myNames as $key => $value){
  echo $key.': '.$value.'
'; }

while

Контролираме условието

$i = 0;
while( $i < 10 )
{
  echo $i.'
'; $i++; }

switch