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(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>$x = "";</em></td>
| |
− | <td><span class="type"><a href="language.types.string.php" class="type string">string</a></span></td>
| |
− | <td><strong><code>TRUE</code></strong></td>
| |
− | <td><strong><code>FALSE</code></strong></td>
| |
− | <td><strong><code>TRUE</code></strong></td>
| |
− | <td><strong><code>FALSE</code></strong></td>
| |
− | </tr>
| |
− | | |
− | <tr>
| |
− | <td><em>$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>$x = true;</em></td>
| |
− | <td><span class="type"><a href="language.types.boolean.php" class="type boolean">boolean</a></span></td>
| |
− | <td><strong><code>FALSE</code></strong></td>
| |
− | <td><strong><code>FALSE</code></strong></td>
| |
− | <td><strong><code>TRUE</code></strong></td>
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− | <td><strong><code>TRUE</code></strong></td>
| |
− | </tr>
| |
− | | |
− | <tr>
| |
− | <td><em>$x = 1;</em></td>
| |
− | <td><span class="type"><a href="language.types.integer.php" class="type integer">integer</a></span></td>
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− | <td><strong><code>FALSE</code></strong></td>
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− | <td><strong><code>FALSE</code></strong></td>
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− | <td><strong><code>TRUE</code></strong></td>
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− | <td><strong><code>TRUE</code></strong></td>
| |
− | </tr>
| |
− | | |
− | <tr>
| |
− | <td><em>$x = 42;</em></td>
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− | <td><span class="type"><a href="language.types.integer.php" class="type integer">integer</a></span></td>
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− | <td><strong><code>FALSE</code></strong></td>
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− | <td><strong><code>FALSE</code></strong></td>
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− | <td><strong><code>TRUE</code></strong></td>
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− | <td><strong><code>TRUE</code></strong></td>
| |
− | </tr>
| |
− | | |
− | <tr>
| |
− | <td><em>$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>
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− | <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 = "1";</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>$x = "0";</em></td>
| |
− | <td><span class="type"><a href="language.types.string.php" class="type string">string</a></span></td>
| |
− | <td><strong><code>TRUE</code></strong></td>
| |
− | <td><strong><code>FALSE</code></strong></td>
| |
− | <td><strong><code>TRUE</code></strong></td>
| |
− | <td><strong><code>FALSE</code></strong></td>
| |
− | </tr>
| |
− | | |
− | <tr>
| |
− | <td><em>$x = "-1";</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>$x = "php";</em></td>
| |
− | <td><span class="type"><a href="language.types.string.php" class="type string">string</a></span></td>
| |
− | <td><strong><code>FALSE</code></strong></td>
| |
− | <td><strong><code>FALSE</code></strong></td>
| |
− | <td><strong><code>TRUE</code></strong></td>
| |
− | <td><strong><code>TRUE</code></strong></td>
| |
− | </tr>
| |
− | | |
− | <tr>
| |
− | <td><em>$x = "true";</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 = "false";</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.'<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 === | | === 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.'<br />'; |
| + | } |
| | | |
| == while == | | == while == |
| + | |
| + | Контролираме условието |
| + | |
| + | $i = 0; |
| + | while( $i < 10 ) |
| + | { |
| + | echo $i.'<br />'; |
| + | $i++; |
| + | } |
| | | |
| == switch == | | == switch == |
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