php - aspell_new

Description

int aspell_new ( string $master [, string $personal] )
aspell_new() opens up a new dictionary for use with the other aspell functions.

Parameters

master

Language.

personal

Default to empty string.

Return Values

Returns a dictionary link identifier or FALSE on error.

Examples

Example 325. aspell_new() Example

<?php
 

$aspell_link = aspell_new("english");


?>

php - aspell_check_raw

Description

bool aspell_check_raw ( int $dictionary_link, string $word )
aspell_check_raw() checks the spelling of a word, without changing its case or trying to trim it in any way.

Parameters

dictionary_link

The dictionnary link identifier returned by aspell_new().

word

The tested word.

Return Values

Returns TRUE if the spelling is correct, FALSE if not.

Examples

Example 323. aspell_check_raw() Example

<?php

$aspell_link = aspell_new("english");

if (aspell_check_raw($aspell_link, "test")) {
echo "This is a valid spelling";
} else {
echo "Sorry, wrong spelling";
}
?>

php - aspell_check

Description

bool aspell_check ( int $dictionary_link, string $word )
aspell_check() checks the spelling of a word.

Parameters

dictionary_link

The dictionnary link identifier returned by aspell_new().

word

The tested word.

Return Values

Returns TRUE if the spelling is correct, FALSE if not.

Examples

Example 324. aspell_check() Example

<?php

$aspell_link = aspell_new("english");

if (aspell_check($aspell_link, "testt")) {
echo "This is a valid spelling";
} else {
echo "Sorry, wrong spelling";
}
?>

php - asort

Description

bool asort ( array &$array [, int $sort_flags] )
This function sorts an array such that array indices maintain their correlation with the array elements they are associated with. This is used mainly when sorting associative arrays where the actual element order is significant.
Returns TRUE on success or FALSE on failure.

Example 292. asort() example

<?php
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");asort($fruits);
foreach ($fruits as $key => $val) {
echo "$key = $val\n";
}


?>

  The above example will output:

c = apple
b = banana
d = lemon
a = orange

php - asin

Description

float asin ( float $arg )
Returns the arc sine of arg in radians. asin() is the complementary function of sin(), which means that a==sin(asin(a)) for every value of a that is within asin()'s range.

Parameters

arg

The argument to process

Return Values

The arc sine of arg in radians

php - ascii2ebcdic

Description

int ascii2ebcdic ( string $ascii_str )
ascii2ebcdic() is an Apache-specific function which is available only on EBCDIC based operating systems (OS/390, BS2000). It translates the ASCII encoded string ascii_str to its equivalent EBCDIC representation (binary safe), and returns the result.

Parameters

ascii_str

The ASCII string that will be translated.

Return Values

The EBCDIC representation of an ASCII string.

php - arsort

Description

bool arsort ( array &$array [, int $sort_flags] )
This function sorts an array such that array indices maintain their correlation with the array elements they are associated with. This is used mainly when sorting associative arrays where the actual element order is significant.
Returns TRUE on success or FALSE on failure.

Example 291. arsort() example

<?php
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");arsort($fruits);
foreach ($fruits as $key => $val) {
echo "$key = $val\n";
}
?> 
The above example will output:

a = orange
d = lemon
b = banana
c = apple

php - Arrays

An array in PHP is actually an ordered map. A map is a type that maps values to keys. This type is optimized in several ways, so you can use it as a real array, or a list (vector), hashtable (which is an implementation of a map), dictionary, collection, stack, queue and probably more. Because you can have another PHP array as a value, you can also quite easily simulate trees.
Explanation of those data structures is beyond the scope of this manual, but you'll find at least one example for each of them. For more information we refer you to external literature about this broad topic.

Syntax

Specifying with array()

An array can be created by the array() language-construct. It takes a certain number of comma-separated key => value pairs.

array(  key =>  value
     , ...
     )
// key may be an integer or string
// value may be any value
      

<?php
$arr = array("foo" => "bar", 12 => true);
echo $arr["foo"]; // bar
echo $arr[12]; // 1
?>

A key may be either an integer or a string. If a key is the standard representation of an integer, it will be interpreted as such (i.e. "8" will be interpreted as 8, while "08" will be interpreted as "08"). Floats in key are truncated to integer. There are no different indexed and associative array types in PHP; there is only one array type, which can both contain integer and string indices.
A value can be of any PHP type.

<?php
$arr = array("somearray" => array(6 => 5, 13 => 9, "a" => 42));
echo $arr["somearray"][6]; // 5
echo $arr["somearray"][13]; // 9
echo $arr["somearray"]["a"]; // 42
?>

If you do not specify a key for a given value, then the maximum of the integer indices is taken, and the new key will be that maximum value + 1. If you specify a key that already has a value assigned to it, that value will be overwritten.

<?php
// This array is the same as ...
array(5 => 43, 32, 56, "b" => 12);
// ...this array
array(5 => 43, 6 => 32, 7 => 56, "b" => 12);
?>

Warning As of PHP 4.3.0, the index generation behaviour described above has changed. Now, if you append to an array in which the current maximum key is negative, then the next key created will be zero (0). Before, the new index would have been set to the largest existing key + 1, the same as positive indices are.

Using TRUE as a key will evaluate to integer 1 as key. Using FALSE as a key will evaluate to integer 0 as key. Using NULL as a key will evaluate to the empty string. Using the empty string as key will create (or overwrite) a key with the empty string and its value; it is not the same as using empty brackets.
You cannot use arrays or objects as keys. Doing so will result in a warning: Illegal offset type.

Creating/modifying with square-bracket syntax

You can also modify an existing array by explicitly setting values in it.
This is done by assigning values to the array while specifying the key in brackets. You can also omit the key, add an empty pair of brackets ("[]") to the variable name in that case.

$arr[key] = value;
$arr[] = value;
// key may be an integer or string
// value may be any value
      

If $arr doesn't exist yet, it will be created. So this is also an alternative way to specify an array. To change a certain value, just assign a new value to an element specified with its key. If you want to remove a key/value pair, you need to unset() it.

<?php
$arr = array(5 => 1, 12 => 2);
$arr[] = 56; // This is the same as $arr[13] = 56;
// at this point of the script
$arr["x"] = 42; // This adds a new element to
// the array with key "x"
unset($arr[5]); // This removes the element from the array
unset($arr); // This deletes the whole array
?>

Note: As mentioned above, if you provide the brackets with no key specified, then the maximum of the existing integer indices is taken, and the new key will be that maximum value + 1 . If no integer indices exist yet, the key will be 0 (zero). If you specify a key that already has a value assigned to it, that value will be overwritten.

Warning As of PHP 4.3.0, the index generation behaviour described above has changed. Now, if you append to an array in which the current maximum key is negative, then the next key created will be zero (0). Before, the new index would have been set to the largest existing key + 1, the same as positive indices are.

Note that the maximum integer key used for this need not currently exist in the array. It simply must have existed in the array at some time since the last time the array was re-indexed. The following example illustrates:

<?php// Create a simple array.

$array = array(1, 2, 3, 4, 5);print_r($array);
// Now delete every item, but leave the array itself intact:

foreach ($array as $i => $value) {
 unset($array[$i]);
}

print_r($array);
// Append an item (note that the new key is 5, instead of 0 as you
// might expect).

$array[] = 6;print_r($array);
// Re-index:

$array = array_values($array);$array[] = 7;print_r($array); 

?> 

The above example will output:

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
)
Array
(
)
Array
(
    [5] => 6
)
Array
(
    [0] => 6
    [1] => 7
)

       

Useful functions

There are quite a few useful functions for working with arrays. See the array functions section.

Note: The unset() function allows unsetting keys of an array. Be aware that the array will NOT be reindexed. If you only use "usual integer indices" (starting from zero, increasing by one), you can achieve the reindex effect by using array_values().

<?php
$a = array(1 => 'one', 2 => 'two', 3 => 'three');
unset($a[2]);/* will produce an array that would have been defined as
$a = array(1 => 'one', 3 => 'three');
and NOT
$a = array(1 => 'one', 2 =>'three');
*/
$b = array_values($a);// Now $b is array(0 => 'one', 1 =>'three')

?>

The foreach control structure exists specifically for arrays. It provides an easy way to traverse an array.

Array do's and don'ts

Why is $foo[bar] wrong?

You should always use quotes around a string literal array index. For example, use $foo['bar'] and not $foo[bar]. But why is $foo[bar] wrong? You might have seen the following syntax in old scripts:

<?php
$foo[bar] = 'enemy';
echo $foo[bar];// etc
?>

This is wrong, but it works. Then, why is it wrong? The reason is that this code has an undefined constant (bar) rather than a string ('bar' - notice the quotes), and PHP may in future define constants which, unfortunately for your code, have the same name. It works because PHP automatically converts a bare string (an unquoted string which does not correspond to any known symbol) into a string which contains the bare string. For instance, if there is no defined constant named bar, then PHP will substitute in the string 'bar' and use that.

Note: This does not mean to always quote the key. You do not want to quote keys which are constants or variables, as this will prevent PHP from interpreting them.

<?php
error_reporting(E_ALL);

ini_set('display_errors', true);

ini_set('html_errors', false);// Simple array:

$array = array(1, 2);$count = count($array);
for ($i = 0; $i < $count; $i++) {
echo "\nChecking $i: \n";
echo "Bad: " . $array['$i'] . "\n";
echo "Good: " . $array[$i] . "\n";
echo "Bad: {$array['$i']}\n";
echo "Good: {$array[$i]}\n";
}

?>

The above example will output:

Checking 0: 
Notice: Undefined index:  $i in /path/to/script.html on line 9
Bad: 
Good: 1
Notice: Undefined index:  $i in /path/to/script.html on line 11
Bad: 
Good: 1

Checking 1: 
Notice: Undefined index:  $i in /path/to/script.html on line 9
Bad: 
Good: 2
Notice: Undefined index:  $i in /path/to/script.html on line 11
Bad: 
Good: 2
        
      

More examples to demonstrate this fact:

<?php// Let's show all errors
error_reporting(E_ALL);
$arr = array('fruit' => 'apple', 'veggie' => 'carrot');
// Correct
print $arr['fruit']; // apple
print $arr['veggie']; // carrot

// Incorrect. This works but also throws a PHP error of
// level E_NOTICE because of an undefined constant named fruit
//
// Notice: Use of undefined constant fruit - assumed 'fruit' in...
print $arr[fruit]; // apple

// Let's define a constant to demonstrate what's going on. We
// will assign value 'veggie' to a constant named fruit.
define('fruit', 'veggie');
// Notice the difference now
print $arr['fruit']; // apple
print $arr[fruit]; // carrot

// The following is okay as it's inside a string. Constants are not
// looked for within strings so no E_NOTICE error here
print "Hello $arr[fruit]"; // Hello apple

// With one exception, braces surrounding arrays within strings
// allows constants to be looked for
print "Hello {$arr[fruit]}"; // Hello carrot
print "Hello {$arr['fruit']}"; // Hello apple

// This will not work, results in a parse error such as:
// Parse error: parse error, expecting T_STRING' or T_VARIABLE' or T_NUM_STRING'
// This of course applies to using superglobals in strings as well
print "Hello $arr['fruit']";
print "Hello $_GET['foo']";
// Concatenation is another option
print "Hello " . $arr['fruit']; // Hello apple
?>

When you turn error_reporting() up to show E_NOTICE level errors (such as setting it to E_ALL) then you will see these errors. By default, error_reporting is turned down to not show them.
As stated in the syntax section, there must be an expression between the square brackets ('[' and ']'). That means that you can write things like this:

<?php
echo $arr[somefunc($bar)];
?>

This is an example of using a function return value as the array index. PHP also knows about constants, as you may have seen the E_* ones before.

<?php
$error_descriptions[E_ERROR] = "A fatal error has occured";
$error_descriptions[E_WARNING] = "PHP issued a warning";
$error_descriptions[E_NOTICE] = "This is just an informal notice";
?>

Note that E_ERROR is also a valid identifier, just like bar in the first example. But the last example is in fact the same as writing:

<?php
$error_descriptions[1] = "A fatal error has occured";
$error_descriptions[2] = "PHP issued a warning";
$error_descriptions[8] = "This is just an informal notice";
?>

because E_ERROR equals 1, etc.
As we already explained in the above examples, $foo[bar] still works but is wrong. It works, because bar is due to its syntax expected to be a constant expression. However, in this case no constant with the name bar exists. PHP now assumes that you meant bar literally, as the string "bar", but that you forgot to write the quotes.

So why is it bad then?

At some point in the future, the PHP team might want to add another constant or keyword, or you may introduce another constant into your application, and then you get in trouble. For example, you already cannot use the words empty and default this way, since they are special reserved keywords.

Note: To reiterate, inside a double-quoted string, it's valid to not surround array indexes with quotes so "$foo[bar]" is valid. See the above examples for details on why as well as the section on variable parsing in strings.

Converting to array

For any of the types: integer, float, string, boolean and resource, if you convert a value to an array, you get an array with one element (with index 0), which is the scalar value you started with.
If you convert an object to an array, you get the properties (member variables) of that object as the array's elements. The keys are the member variable names with a few notable exceptions: private variables have the class name prepended to the variable name; protected variables have a '*' prepended to the variable name. These prepended values have null bytes on either side. This can result in some unexpected behaviour.

<?php
class A {
private $A; // This will become '\0A\0A'}

class B extends A {
private $A; // This will become '\0B\0A'
public $AA; // This will become 'AA'}
var_dump((array) new B());
?>

The above will appear to have two keys named 'AA', although one of them is actually named '\0A\0A'.
If you convert a NULL value to an array, you get an empty array.

Comparing

It is possible to compare arrays by array_diff() and by Array operators.

Examples

The array type in PHP is very versatile, so here will be some examples to show you the full power of arrays.

<?php// this$a = array( 'color' => 'red',
'taste' => 'sweet',
'shape' => 'round',
'name' => 'apple',
4 // key will be 0
);
// is completely equivalent with
$a['color'] = 'red';$a['taste'] = 'sweet';$a['shape'] = 'round';$a['name'] = 'apple';
$a[] = 4; // key will be 0
$b[] = 'a';
$b[] = 'b';
$b[] = 'c';// will result in the array array(0 => 'a' , 1 => 'b' , 2 => 'c'),
// or simply array('a', 'b', 'c')
?>

Example 11.6. Using array()

<?php// Array as (property-)map
$map = array( 'version' => 4,
'OS' => 'Linux',
'lang' => 'english',
'short_tags' => true
);
// strictly numerical keys
$array = array( 7,
8,
0,
156,
-10
);// this is the same as array(0 => 7, 1 => 8, ...)
$switching = array( 10, // key = 0
5 => 6,
3 => 7,
'a' => 4,
11, // key = 6 (maximum of integer-indices was 5)
'8' => 2, // key = 8 (integer!)
'02' => 77, // key = '02'
0 => 12 // the value 10 will be overwritten by 12
);
// empty array
$empty = array(); 
?>

Example 11.7. Collection

<?php
$colors = array('red', 'blue', 'green', 'yellow');

foreach ($colors as $color) {
echo "Do you like $color?\n";
}
?> 
The above example will output:

Do you like red?
Do you like blue?
Do you like green?
Do you like yellow?

     

Changing values of the array directly is possible since PHP 5 by passing them as reference. Prior versions need workaround:

Example 11.8. Collection

<?php// PHP 5foreach ($colors as &$color) {
$color = strtoupper($color);
}
unset($color); /* ensure that following writes to
$color will not modify the last array element */

// Workaround for older versions
foreach ($colors as $key => $color) {
$colors[$key] = strtoupper($color);
}
print_r($colors);
?> 
The above example will output:

Array
(
    [0] => RED
    [1] => BLUE
    [2] => GREEN
    [3] => YELLOW
)

      

This example creates a one-based array.

Example 11.9. One-based index

<?php
$firstquarter = array(1 => 'January', 'February', 'March');
print_r($firstquarter);
?> 
The above example will output:

Array 
(
    [1] => 'January'
    [2] => 'February'
    [3] => 'March'
)
   
      

Example 11.10. Filling an array

<?php// fill an array with all items from a directory
$handle = opendir('.');
while (false !== ($file = readdir($handle))) {
$files[] = $file;
}closedir($handle); 
?>

Arrays are ordered. You can also change the order using various sorting functions. See the array functions section for more information. You can count the number of items in an array using the count() function.

Example 11.11. Sorting an array

<?php
sort($files);
print_r($files);
?>

Because the value of an array can be anything, it can also be another array. This way you can make recursive and multi-dimensional arrays.

Example 11.12. Recursive and multi-dimensional arrays

<?php
$fruits = array ( "fruits" => array ( "a" => "orange",
"b" => "banana",
"c" => "apple"
),
"numbers" => array ( 1,
2,
3,
4,
5,
6
),
"holes" => array ( "first",
5 => "second",
"third"
)
);
// Some examples to address values in the array above 
echo $fruits["holes"][5]; // prints "second"
echo $fruits["fruits"]["a"]; // prints "orange"
unset($fruits["holes"][0]); // remove "first"

// Create a new multi-dimensional array$juices["apple"]["green"] = "good"; 


?>

You should be aware that array assignment always involves value copying. It also means that the internal array pointer used by current() and similar functions is reset. You need to use the reference operator to copy an array by reference.

<?php
$arr1 = array(2, 3);$arr2 = $arr1;$arr2[] = 4; // $arr2 is changed,
// $arr1 is still array(2, 3)
$arr3 = &$arr1;$arr3[] = 4; // now $arr1 and $arr3 are the 


?>

php - ArrayObject::getIterator

Description
ArrayIterator ArrayObject::getIterator ( void )

This function will return an iterator from an ArrayObject.

Example 2296. ArrayObject::getIterator() example

<?php


$array = array('1' => 'one',
'2' => 'two',
'3' => 'three');
$arrayobject = new ArrayObject($array);
$iterator = $arrayobject->getIterator();

while($iterator->valid()) {
echo $iterator->key() . ' => ' . $iterator->current() . "\n";

$iterator->next();
}


?>

The above example will output:

1 => one
2 => two
3 => three

php - ArrayObject::__construct

Description
ArrayObject ArrayObject::__construct ( mixed $input )

This constructs a new array object. The input parameter accepts an array or another ArrayObject.


Example 2295. ArrayObject::__construct() example

'one',
'2' => 'two',
'3' => 'three');

$arrayobject = new ArrayObject($array);

var_dump($arrayobject);
?>
The above example will output:


object(ArrayObject)#1 (3) {
[1]=>
string(3) "one"
[2]=>
string(3) "two"
[3]=>
string(5) "three"
}

php - ArrayIterator::valid

Description

bool ArrayIterator::valid ( void )
This function checks if the array contains any more entries.

Example 2294. ArrayIterator::valid() example

<?php


$array = array('1' => 'one');
$arrayobject = new ArrayObject($array);$iterator = $arrayobject->getIterator();
var_dump($iterator->valid()); //bool(true)
$iterator->next(); // advance to the next item

//bool(false) because there is only one array element 

var_dump($iterator->valid());


?>

php - ArrayIterator::rewind

Description

void ArrayIterator::rewind ( void )
This function rewinds the iterator to the beginning.

Example 2293. ArrayIterator::rewind() example

<?php


$arrayobject = new ArrayObject();
$arrayobject[] = 'zero';$arrayobject[] = 'one';$arrayobject[] = 'two';
$iterator = $arrayobject->getIterator();
$iterator->next();
echo $iterator->key(); //1
$iterator->rewind(); //rewinding to the beginingecho $iterator->key(); //0


?>

php - ArrayIterator::next

Description

void ArrayIterator::next ( void )
This function moves the iterator to the next entry.

Example 2292. ArrayIterator::next() example

<?php


$arrayobject = new ArrayObject();
$arrayobject[] = 'zero';$arrayobject[] = 'one';
$iterator = $arrayobject->getIterator();

while($iterator->valid()) {
echo $iterator->key() . ' => ' . $iterator->current() . "\n";

$iterator->next();
}


?>

  The above example will output:

0 => zero
1 => one

php - ArrayIterator::key

Description

mixed ArrayIterator::key ( void )
This function returns the current array key

Example 2291. ArrayIterator::key() example

<?php
$array = array('key' => 'value');
$arrayobject = new ArrayObject($array);$iterator = $arrayobject->getIterator();

echo $iterator->key(); //key 
?>

php - ArrayIterator::current

Description

mixed ArrayIterator::current ( void )
This function returns the current array entry

Example 2290. ArrayIterator::current() example

<?php
 

$array = array('1' => 'one',
'2' => 'two',
'3' => 'three');
$arrayobject = new ArrayObject($array);

for($iterator = $arrayobject->getIterator();
$iterator->valid();
$iterator->next()) {

echo $iterator->key() . ' => ' . $iterator->current() . "\n";
}


?>

  The above example will output:

1 => one
2 => two
3 => three

php - array_walk_recursive

Description

bool array_walk_recursive ( array &$input, callback $funcname [, mixed $userdata] )
Applies the user-defined function funcname to each element of the input array. This function will recur into deeper arrays. Typically, funcname takes on two parameters. The input parameter's value being the first, and the key/index second. If the optional userdata parameter is supplied, it will be passed as the third parameter to the callback funcname.
Returns TRUE on success or FALSE on failure.

Note: If funcname needs to be working with the actual values of the array, specify the first parameter of funcname as a reference. Then, any changes made to those elements will be made in the original array itself.

Example 285. array_walk_recursive() example

<?php
$sweet = array('a' => 'apple', 'b' => 'banana');$fruits = array('sweet' => $sweet, 'sour' => 'lemon');

function test_print($item, $key)
{
echo "$key holds $item\n";
}
array_walk_recursive($fruits, 'test_print');


?>

  The above example will output:
a holds apple
b holds banana
sour holds lemon

php - array_walk

Description

bool array_walk ( array &$array, callback $funcname [, mixed $userdata] )
Returns TRUE on success or FALSE on failure.
Applies the user-defined function funcname to each element of the array array. Typically, funcname takes on two parameters. The array parameter's value being the first, and the key/index second. If the optional userdata parameter is supplied, it will be passed as the third parameter to the callback funcname.
If function funcname requires more parameters than given to it, an error of level E_WARNING will be generated each time array_walk() calls funcname. These warnings may be suppressed by prepending the PHP error operator @ to the array_walk() call, or by using error_reporting().

Note: If funcname needs to be working with the actual values of the array, specify the first parameter of funcname as a reference. Then, any changes made to those elements will be made in the original array itself.

Note: Passing the key and userdata to funcname was added in 4.0.0

array_walk() is not affected by the internal array pointer of array. array_walk() will walk through the entire array regardless of pointer position.
Users may not change the array itself from the callback function. e.g. Add/delete elements, unset elements, etc. If the array that array_walk() is applied to is changed, the behavior of this function is undefined, and unpredictable.

Example 286. array_walk() example

<?php
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");

function test_alter(&$item1, $key, $prefix)
{
$item1 = "$prefix: $item1";
}

function test_print($item2, $key)
{
echo "$key. $item2<br />\n";
}

echo "Before ...:\n";array_walk($fruits, 'test_print');
array_walk($fruits, 'test_alter', 'fruit');
echo "... and after:\n";
array_walk($fruits, 'test_print');


?>

 The above example will output:
Before ...:
d. lemon
a. orange
b. banana
c. apple
... and after:
d. fruit: lemon
a. fruit: orange
b. fruit: banana
c. fruit: apple