PHP/Data Structure/Associate Array — различия между версиями
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Версия 10:37, 26 мая 2010
Содержание
- 1 An array called $computers with numeric and string keys
- 2 An array called $vegetables with string keys
- 3 Argument Swapping
- 4 array_intersect_assoc: Computes the intersection of arrays with additional index check
- 5 array_key_exists
- 6 array_keys: Return all the keys of an array
- 7 Arrays Using Associative Array Notation
- 8 Array to object
- 9 array_values: Return all the values of an array
- 10 Assigning and Comparing
- 11 Associative Arrays
- 12 Building an array of defaults
- 13 Creates an array that assigns keys 1 through 7 to the days of the week.
- 14 Creates an array with keys "a", "b" and "c with values of 1, 2 and 3 as well as keys 0, 1 and 2 with values "a", "b", and "c"
- 15 Creating an associative array of shapes
- 16 Creating Arrays
- 17 Displaying one value from an array
- 18 foreach statement is used to loop through an associative array
- 19 key: Fetch a key from an associative array
- 20 Looping Through an Associative Array with foreach
- 21 Obtaining Array Keys and Values
- 22 Obtaining Array Keys with a Given Value
- 23 One-based array index
- 24 print_r: output associate array
- 25 Reference the assiciate array element
- 26 Sort associate array
- 27 Use foreach, while and list to loop through associate array
- 28 Using both the array key and a passed-in value to modify each element value
- 29 Using Variable Variables to Create Associations
An array called $computers with numeric and string keys
<?
$computers["t"] = "A";
$computers[2] = "B";
$computers["A"] = "C";
?>
An array called $vegetables with string keys
<?
$vegetables["corn"] = "yellow";
$vegetables["beet"] = "red";
$vegetables["carrot"] = "orange";
?>
Argument Swapping
<?php
$dates = array(
array( "mon"=> 12, "mday"=>25, "year"=>2001 ),
array( "mon"=> 5, "mday"=>23, "year"=>2000 ),
array( "mon"=> 10, "mday"=>29, "year"=>2001 )
);
$format = include ("local_format.php");
foreach ($dates as $date) {
printf( "$format", $date["mon"], $date["mday"], $date["year"] );
}
?>
array_intersect_assoc: Computes the intersection of arrays with additional index check
<?php
$array1 = array("OH" => "Ohio", "CA" => "California", "HI" => "Hawaii");
$array2 = array("50" => "Hawaii", "CA" => "California", "OH" => "Ohio");
$array3 = array("TX" => "Texas", "MD" => "Maryland", "OH" => "Ohio");
$intersection = array_intersect_assoc($array1, $array2, $array3);
print_r($intersection);
?>
array_key_exists
<?php
$state["Delaware"] = "December 7, 1787";
$state["Pennsylvania"] = "December 12, 1787";
$state["Ohio"] = "March 1, 1803";
if (array_key_exists("Ohio", $state)) echo "Ohio joined the Union on $state[Ohio]";
?>
array_keys: Return all the keys of an array
<?php
$state["Delaware"] = "December 7, 1787";
$state["Pennsylvania"] = "December 12, 1787";
$state["New Jersey"] = "December 18, 1787";
$keys = array_keys($state);
print_r($keys);
// Array ( [0] => Delaware [1] => Pennsylvania [2] => New Jersey )
?>
Arrays Using Associative Array Notation
<html>
<head>
<title>Associative Array Notation</title>
</head>
<body>
<?php
$cars = array(
"1" => array ("A", "B", "C"),
"2" => array ("D", "E", "F", "G"),
"3" => array ("H", "I")
);
ob_start();
var_dump($cars);
$cars_var_dump = ob_get_contents();
ob_end_clean();
print("<pre>" . $cars_var_dump . "</pre>");
?>
</body>
</html>
Array to object
<?php
$arr = array(
"abc" => "abc",
"def" => 123.5,
"ghi" => array(1,2,3),
0 => "def"
);
$key = "abc";
$obj = (object) $arr;
echo "First value = $obj->abc\n";
echo "Second value = $obj->def\n";
echo "Third value = $obj->ghi\n";
?>
array_values: Return all the values of an array
<?php
$population = array("Ohio" => "11,421,267", "Iowa" => "2,936,760");
$popvalues = array_values($population);
print_r($popvalues);
// Array ( [0] => 11,421,267 [1] => 2,936,760 )
?>
Assigning and Comparing
<?php
$a = array(0=>1,2=>"orange","id"=>7,"name"=>"John" );
print_r($a);
?>
Associative Arrays
<?php
$emp_det [Name] = "Name";
$emp_det [Age] = "2";
$emp_det [Code] = "8";
$emp_det [Designation] = "System Administrator";
echo $emp_det[Name];
$emp_det = array (Name => "Name", Age => "24", Code => "System Administrator");
echo $emp_det[Name];
?>
Building an array of defaults
if ($_POST["_submit_check"]) {
$defaults = $_POST;
} else {
$defaults = array("delivery" => "yes",
"size" => "medium",
"main_dish" => array("taro","tripe"),
"sweet" => "cake");
}
Creates an array that assigns keys 1 through 7 to the days of the week.
<?
$days = array(1=>"Sunday", "Monday", "Tuesday","Wednesday", "Thursday", "Friday", "Saturday");
?>
Creates an array with keys "a", "b" and "c with values of 1, 2 and 3 as well as keys 0, 1 and 2 with values "a", "b", and "c"
<?
$myarray = array("a"=>1, "a", "b"=>2, "b", "c"=>3, "c");
?>
Creating an associative array of shapes
<?php
$shapes = array("S" => "Cylinder",
"N" => "Rectangle",
"A" => "Sphere",
"O" => "Sphere",
"P" => "Rectangle");
?>
Creating Arrays
<?php
$my_array = array();
$pets = array("A", "S", "B", "W");
$person = array("B", "J", 24, "CA");
$customer = array("first" => "Bill", "last" => "Jones","age" => 24, "state" => "CA");
print "<p>Pet number 1 is named "$pets[0]".</p>\n";
print "<p>The person"s age is $person[2].</p>\n";
print "<p>The customer"s age is {$customer["age"]}.</p>\n";
?>
Displaying one value from an array
<?php
$shapes = array("S" => "Cylinder",
"N" => "Rectangle",
"A" => "Sphere",
"O" => "Sphere",
"P" => "Rectangle");
print "A notepad is a {$shapes["Notepad"]}.";
?>
foreach statement is used to loop through an associative array
<?php
$emp_det = array (Name => "A",
Age => "2" ,
Code =>"8",
Designation => "Administrator");
foreach ($emp_det as $key=>$temp) {
echo "$key = $temp","\n";
}
?>
key: Fetch a key from an associative array
<?php
$capitals = array("Ohio" => "Columbus", "Iowa" => "Des Moines","Arizona" => "Phoenix");
echo "<p>Can you name the capitals of these states?</p>";
while($key = key($capitals)) {
echo $key."<br />";
next($capitals);
}
?>
Looping Through an Associative Array with foreach
<html>
<head>
<title>Looping Through an Associative Array with foreach</title>
</head>
<body>
<?php
$character = array (name=>"Joe",
occupation=>"Programmer",
age=>30,
"Learned language "=>"Java"
);
foreach ( $character as $key=>$val ){
print "$key = $val<br>";
}
?>
</body>
</html>
Obtaining Array Keys and Values
<?php
function array_display($array, $pre=FALSE){
$tag = $pre ? "pre" : "p";
printf("<%s>%s</%s>\n", $tag, var_export($array, TRUE), $tag);
}
$fruits = array("red" => "apple", "yellow" => "banana", "green" => "lime");
$colors = array_keys($fruits);
$flavors = array_values($fruits);
array_display($fruits);
array_display($colors);
array_display($flavors);
?>
Obtaining Array Keys with a Given Value
<?php
$countries = array( "USA" => "English", "Spain" => "Spanish",
"France" => "French", "Argentina" => "Spanish");
function array_get_keys($search, $array)
{
$keys = array();
foreach($array as $key => $value)
if($value == $search)
$keys[] = $key;
if(count($keys) == 0)
$keys = FALSE;
return $keys;
}
$language = "Spanish";
$spoken = array_get_keys($language, $countries);
printf("<p>Countries where %s is spoken: %s.</p>\n",
$language,
$spoken ? implode(", ", $spoken) : "None");
$language = "Tagalog";
$spoken = array_get_keys($language, $countries);
printf("<p>Countries where %s is spoken: %s.</p>\n",
$language,
$spoken ? implode(", ", $spoken) : "None");
?>
One-based array index
<html>
<head>
<title>One-based array index</title>
</head>
<body>
<ol>
<?php
$arr = array( 1 => "1st", "2nd", "3rd", "4th", "5th" );
for( $i = 1; $i <= sizeof($arr); $i++ )
{
echo("Position $i - Element value: $arr[$i]<br>");
}
?>
</ol>
</body>
</html>
print_r: output associate array
<?php
$states = array (
"Ohio" => array ("population" => "11,353,140", capital => "Columbus"),
"Nebraska" => array("population" => "1,711,263", capital => "Omaha")
)
print_r($states);
?>
Reference the assiciate array element
<?
$birthdays["K"] = "1988-04-12";
$birthdays["S"] = "1986-05-16";
$birthdays["D"] = "1983-02-09";
echo("My birthday is: " . $birthdays["K"]);
?>
Sort associate array
<?php
$states = array("OH" => "Ohio", "CA" => "California", "MD" => "Maryland");
sort($states);
print_r($states);
?>
Use foreach, while and list to loop through associate array
<?php
$characters = array(
array(
"name" => "A",
"occupation" => "A1",
"age" => 30,
"special power" => "A3"
),
array(
"name" => "B",
"occupation" => "B1",
"age" => 24,
"special power" => "B2"
),
array(
"name" => "C",
"occupation" => "C1",
"age" => 45,
"special power" => "C2"
)
);
foreach ($characters as $c) {
while (list($k, $v) = each ($c)) {
echo "$k ... $v <br/>";
}
}
?>
Using both the array key and a passed-in value to modify each element value
<?php
function change(&$element, $key, $mark) {
$element = "$mark$key$mark, the $element";
}
$dogs = array("A" => "C", "B" => "D", "X" => "Z");
array_display($dogs, TRUE);
array_walk($dogs, "change", "*");
array_display($dogs, TRUE);
?>
Using Variable Variables to Create Associations
<?php
$favorite_color = "blue";
$favorite_weapon = "gun";
$favorite_drink = "beer";
$favorite_things = array("color", "weapon", "drink");
foreach ($favorite_things as $thing) {
echo "<p>", $thing, " = ", ${"favorite_{$thing}"}, "</p>";
}
?>