PHP语言中的数组使用方式。

Hafenkranich发布于2018/06/08 00:00

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1.Chapter - 3 Arrays PHP: Hypertext Preprocessor

2.Outline What is an array ? Indexed array Associative array Multidimensional array 

3.What is an Array? An array is a special variable, which can store multiple values in one single variable. An array can hold many values under a single name, and you can access the values by referring to an index number.

4.What is an array? However, what if you want to loop through the cars and find a specific one? And what if you had not 3 cars, but 300? The best solution here is to use an array! An array can hold all your variable values under a single name. And you can access the values by referring to the array name. Each element in the array has its own index so that it can be easily accessed.

5.What is an array? In PHP, the array() function is used to create an array: array ();

6.Kind of arrays in PHP Indexed  array  - An array with a numeric index Associative array  - An array where each ID key is associated with a value Multidimensional array  - An array containing one or more arrays

7.Indexed Arrays A numeric array stores each array element with a numeric index. There are two ways to create indexed arrays:

8.Indexed Arrays In the following example the index are automatically assigned (the index starts at 0 ): - $cars = array (" Saab","Volvo","BMW","Toyota "); The following example we assign the index manually :] $ cars[0]="Saab "; $ cars[1]="Volvo "; $ cars[2]="BMW "; $ cars[3]="Toyota"; $ array_name = array(val1, val2, val3,val4 ,……);

9.Indexed Arrays - Example <? php $cars[0]="Saab"; $cars[1]="Volvo"; $cars[2]="BMW"; $cars[3]="Toyota";  echo $cars[0] . " and " . $cars[1] . " are Swedish cars."; ?>

10.Indexed Arrays - Example <? php $array =  array (1, 2,3,4,5,6,7,8,9); for ($ i  = 0; $ i  < 9; $ i ++)   {      echo “Number : “. $array[$ i ]; } ?>

11.Print_r () Function Print construction of array as group of locations and the value stored in it print_r ($ expression [, bool $return = false ] )

12.Print_r () <? php $ arr = array(1,2,3,4,5); Print_r ($ arr ); ?> Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 )

13.Count() Function This is build in function ,counts all elements in an array, or something in an object . int count ($ var [, int $mode = COUNT_NORMAL ] )

14.Count Function - Example <? php $a[0] = 1; $a[1] = 3; $a[2] = 5; $result = count($a ); //  $result ==  3 $b[0]  = 7; $b[5]  = 9; $b[10] = 11; $result = count($b ); //  $result ==  3 $result = count(null );//  $result ==  0 $result = count(false );//  $result == 1 ?>

15.Count Function - Example <? php $array =  array (“M”, ” u”,”n”,”e”,”e”,”r ”); for ($ i  = 0; $ i  <  count ($array); $ i ++)   {      echo  $array[$ i ]; } ?>

16.Count Function - Example <? php $array =  array (“M”, ” u”,”n”,”e”,”e”,”r ”); for ($ i  = 0; $ i  <  count ($array); $ i ++)   {      echo  $array[$ i ]; } ?>

17.Foreach - Example <? php $x=array(" one","two","three "); foreach ($x as $value)   {   echo $value . "< br />";   } ?>

18.Foreach - Example <? php $colors =  array (red, blue, green, yellow); foreach  ($colors as $color) {     echo "Do you like $color?

19.in_array () Function The in_array () function searches an array for a specific value . This function returns TRUE if the value is found in the array, or FALSE otherwise. in_array ( search,array,type ) Parameter Description search Required. Specifies the what to search for array Required. Specifies the array to search type Optional. If this parameter is set, the in_array () function searches for the search-string and specific type in the array Note :  If the search parameter is a string and the type parameter is set to TRUE, the search is case-sensitive.

20.in_array () Function - Example <? php $ os  =  array ("Mac", “W7", “W8", "Linux"); if ( in_array (“XP", $ os )) {     echo "Got XP"; } if ( in_array (“Mac", $ os )) {     echo "Got Mac"; } ?>

21.Associative Arrays An associative array, each ID key is associated with a value. When storing data about specific named values, a numerical array is not always the best way to do it. With associative arrays we can use the values as keys and assign values to them.

22.Associative Arrays $ ages = array ("Peter"=>32, " Quagmire "=>30, "Joe"=>34); or $ ages [Peter] = "32"; $ ages [ Quagmire ] = "30"; $ ages [Joe] = "34"; $ array_name = array ($index1=>$val1, $index1=>$val1,…..);

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

24.Associative Arrays - example <? 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); ?>

25.Associative Arrays - example <? php $ages[Peter] = "32"; $ages[Quagmire] = "30"; $ages[Joe] = "34"; echo "Peter is " . $ages[Peter] . " years old."; ?>

26.Associative Arrays - example <? 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 ?>

27.Associative Arrays - example <? 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 ?>

28.Multidimensional Arrays In a multidimensional array, each element in the main array can also be an array. And each element in the sub-array can be an array, $ myArray = array ( array( value1, value2, value3 ), array( value4, value5, value6 ), array( value7, value8, value9 ) );

29.Multidimensional 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 ”)); echo $fruits["holes"][5];    // prints "second" echo $fruits["fruits"]["a"]; // prints "orange" ?>

30.Multidimensional Arrays <? php $families = array(“capital"=>array(“A“,“B“,“C”),   “small"=>array(“a”, “b”, “c”), “number"=>array(“1“,“2“,”3”)); foreach ($families as $value) { foreach ($value as $values) {echo $values.” ”;} Echo “< br />”} ?>

31.Multidimensional Arrays <? php $try[] = array ("11", "12", "15", "22", "41", "42"); $try[] = array ("6", "7", "16", "17", "22", "23"); $count = count ($try); for ($ i =0; $ i <$count; $ i ++) { $ countmore =count($try[0]); for ($j=0; $j < $ countmore ; $j++) { print (" i$i j$j " . $try[$ i ][$j] . "< br > "); } print ("< br >"); } ?>

32.Multidimensional Arrays <? php $try[] = array ("11", "12", "15", "22", "41", "42"); $try[] = array ("6", "7", "16", "17", "22", "23"); $count = count ($try); for ($ i =0; $ i <$count; $ i ++) { $ countmore =count($try[0]); for ($j=0; $j < $ countmore ; $j++) { print (" i$i j$j " . $try[$ i ][$j] . "< br > "); } print ("< br >"); } ?>

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  • Hafenkranich
  • Independent consultant specializing in database, web and M2M applications

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