PHP Introductory Tutorial Array Usage Summary (create, delete, traverse, sort, etc.)

This example summarizes the usage of PHP arrays. Share to everyone for your reference, as follows:

demo1.php

<?php  //Create an array variable  $userNames = Array (' Zhang San ', ' John Doe ', ' Harry ');  Print this array out//echo $userNames;//array//$userName = ' Zhang San ';//echo $userName;//Zhang San  //If you want to print out an element of this array  // Then you have to find the subscript for this element, key (key)  //0,1,2  //echo $userNames [2];//Harry  //print_r--print easy-to-understand information about the variable.  //print_r ($userNames);//array ([0] = Zhang San [1] = John Doe [2] = = Harry)  //$userNames is an array variable, and $userNames [x] Can The small variable under the array variable  $userNames [4] = ' Zhao Qi ';  Print_r ($userNames);//array ([0] = Zhang San [1] = John Doe [2] = = Harry [4] + Zhao VII)?>

demo2.php

<?php  //range--Create an array containing the specified range of cells  //range contains the specified array  //contains two things, one is called the key (key), a value  //key is automatically generated, By default starting from 0, each time +1  //value is your own assignment  //$numbers = range (1,4);  Print_r ($numbers);  Array ([0] = 1 [1] = 2 [2] = 3 [3] = 4)//$letters = range (' A ', ' e ');//Print_r ($letters);//array ([0] = a [1] = b [2] = c [3] = + d [4] + E)//Echo $letters [3];? >

demo3.php

<?php  $userNames = Array (' Zhang San ', ' John Doe ', ' Harry ');  Loop to display all values in the array  //from 0-5 cycles//for ($i =0; $i <3; $i + +) {//   echo ($i + 1). ' --$userNames [$i]. ' <br/> '//}  /   * 1--> Zhang San   * 2--> John Doe   * 3--> Harry   * *///Echo count ($userNames);//3//for ($ I=0, $i <count ($userNames), $i + +) {//   echo ($i + 1). ' --$userNames [$i]. ' <br/> ';/  /}//If key is not starting from 0, or if it is not a number at all, then it is not possible to use the listless loop to implement the display data list  //iterate through the array through a Foreach loop, which does not need to be considered key// foreach ($userNames as $value) {//   echo $value. ' <br/> ';//}  //foreach traverse $key + $value//foreach ($userNames as $KEYAAA + $value) {//   echo $keyaaa. '--$value. ' <br/> '//}  /**   * 0--> Zhang San   * 1--> John Doe   * 2--> Harry   * *  ///So, you have to make a judgment first  if ( Is_array ($userNames)) {    foreach ($userNames as $key = + $value) {      echo $key. '--$value. ' <br/> ';    }  } else{    echo $userNames;  }? >

demo4.php

<?php  $userNames = Array (' Zhang San ', ' John Doe ', ' Harry ');  Print_r ($userNames);  echo $userNames [0];? >

demo5.php

<?php  //Create an array of custom keys (key)  //If you do not go to declare element key, then calculate from start 0//$userNames = Array (' Baidu ' = ' Zhang San ', ' John Doe ', ' Harry ');// Print_r ($userNames); Array ([Baidu] = Zhang San [0] = John Doe [1] = Harry)  $userNames = Array (' Baidu ' = ' Zhang San ', ' taobao ' = ' John Doe ', ' the ' => ' ;' Harry ');  Print_r ($userNames); Array ([Baidu] = Zhang San [taobao] [John Doe] [] = Harry)  echo $userNames [' Baidu ']; >

demo6.php

<?php  //First create an array of only one element  $userAge = Array (' CHAOYV ' =>25);  Print out the age of Chaoyv  //echo $userAge [' chaoyv '];//25  //Add the previous array, append two, and here say subscript, key, key is a thing  $userAge [' yike '] = ;  $userAge [' wife '] =;  Print_r ($userAge);? >

demo7.php

<?php  //array keyword can not, you can create an array  $userAges [' chaoyv '] =;  Print_r ($userAges); Array ([chaoyv] [=] +)  $userAges [' yike '] =;  $userAges [' wife '] =;  Print_r ($userAges); Array ([CHAOYV] [yike] = [wife] (=)  ///There is no way to use the For loop to display all the data, but only through a foreach traversal  ( $userAges as $value) {    echo $value. ' <br/> ';  }? >

demo8.php

<?php//$userAges [' chaoyv '] = 25;//$userAges [' yike '] = 30;//$userAges [' wife '] =;  $username = Array (' world ' = ' and ' open ', ' blood ' = ' zhao Xue ', ' learn ' and ' Mo Xue ');  Print_r ($username);  each uses//each--Returns the current key/value pair in the array and moves the array pointer forward one step  //There is a pointer, by default, the pointer is the first key value pair  //Here the first key value pair is ' world ' + ' how open '  //If each ($username), then get the first key value to '//each ' and ' open ' the  function returns an array,  //each the first key-value pair, and wraps it into a new array.  //print_r (each ($username));  Equivalent to $a = Array ([1] = where open [value] and where [0] = [key] = world)  //$a = each ($username);  echo $a [value];  Print_r (each ($username));  Echo ' <br/> ';  Print_r (each ($username));? >

demo9.php

<?php  $username = Array (' world ' = ' and ' he ', ' blood ' = ' Zhao blood ', ' learn ' and ' Mo Xue ');  Here, how do we use each to loop all the data?  //equal to $a = Array ([1] = where [value] = [0] = [key] = world)  //Two exclamation point, which indicates that the data that really exists is converted to Boolean//echo!! each ($username);//Description There is data, there is data, with the idea of Boolean value is True (TRUE)//echo!! each ($username);//echo!! each ($username);//echo!! each ($username);//fourth is false while  (!! $a = each ($username)) {    echo $a [' key ']. ' --$a [' value ']. ' <br/> ';  } $a = each ($username);//Echo $a [0]. ' ---'. $a [1]. ' <br/> ';//$a = each ($username);//Echo $a [0]. ' ---'. $a [1]. ' <br/> ';//$a = each ($username);//Echo $a [0]. ' ---'. $a [1]. ' <br/> ';///**//  * World---How to open//  * Blood---zhao blood//  * Learn---mo xue//  * */?>

demo10.php

<?php//$usernames = Array (' World ' = ' ", '" ", ' blood ' = ' zhao Xue '), ' learn ' and ' Mo Xue ');//$a = each ($usernames);////----/Echo $a [' key '];//echo '--',//echo $a [' value '];//$a = each ($usernames);///Blood-to-Zhao blood//echo $a [' key '];//echo '--'; echo $a [' value '];////list--assigns the values in the array to some variables//$a = array (' AAA ', ' BBB ', ' CCC ', ' ddd ');////  Print_r ($a);//array ([0] =& Gt AAA [1] = BBB [2] = CCC [3] = = DDD)//list ($var 1, $var 2, $var 3, $var 4) = $a;//echo $var 4;//$usernames = Array (0 = ' How to open ', ' blood ' and ' Zhao Blood ', ' learning ' and ' xue ', '////list can only know the key for the number of////////The custom string key is unable to use list to identify the//list ($a, $b, $c) = $usernam es;//echo $a;//where open  $usernames = array (' world ' = ' and ' he ', ' blood ' = ' Zhao blood ', ' learning ' and ' ink Learning ');  Equivalent to $a = Array ([1] = where [value] and where open [0] = [key] (the world)  list ($name, $username) = each ($usernames);  echo $username;? >

demo11.php

<?php  $usernames = Array (' world ' = ' and ' he ', ' blood ' = ' Zhao blood ', ' learn ' and ' Mo Xue ');  $a =each ($usernames);  echo $a [key];  $a =each ($usernames);  echo $a [key];  The third time, I want to take the first array of arrays  //As long as the array pointer is adjusted to the first position can be  //reset--the array's internal pointer to the first cell  reset ($usernames);  $a = each ($usernames);  echo $a [key];  The World Blood World?>

demo12.php

<?php//$usernames = Array (' world ' = ' = ' and ' where ', ' environment ' = ' ' where ', ' blood ' = ' Zhao blood ', ' learning ' and ' ink Learning ');//Print_r ($usernames);//Echo ' <br/> ';////array_unique--Removes duplicate values from the array///Creates a new one, and the new array has been removed, the old array intact//$a = Array_unique ($usernames);// Print_r ($a);  $numbers = Array (1,24,2,1,3,4,2,6,4,2,4,56,2,4,5);  Print_r ($numbers);  $newNumbers = Array_unique ($numbers);  Print_r ($newNumbers);? >

demo13.php

<?php $usernames = Array (' the world ' = ' and ' where ', ' the ' ' and ', ') ', '  blood ' = ' Zhao blood ', ' learning ' and ' ink Learning ');  Print_r ($usernames);  Echo ' <br/> ';  Array_flip--Switches the keys and values in the array  $newUsernames = Array_flip ($usernames);  Print_r ($newUsernames);  /**   * Array ([world] = why open [border] and how open [blood] = Zhao blood son [study] = Ink learning)   * Array ([where open] = [Zhao blood son] = blood [mo xue] = > Study)   * */?>

demo14.php

<?php  //Create a single array  $products = Array (    ' Apple ', ' 6 ', ' 28.8 '),    array (' Pork ', ' 2 ', ' 18.8 '),    Array (' Biscuit ', ' 4 ', ' 48.8 ')  );  Print_r ($products);  Take $products first element out of the  //print_r ($products [2]);  Array in array  echo "|". $products [0][0]. "|". $products [0][1]. "|". $products [0][2]. "| <br/> ";  echo "|". $products [1][0]. "|". $products [1][1]. "|". $products [All in all]. "| <br/> ";  echo "|". $products [2][0]. "|". $products [2][1]. "|". $products [2][2]. "| <br/> ";? >

demo15.php

<?php  //Create a single array  $products = Array (    ' Apple ', ' 6 ', ' 28.8 '),    array (' Pork ', ' 2 ', ' 18.8 '),    Array (' Biscuit ', ' 4 ', ' 48.8 ')  );  First, the length of the outer array is requested  //echo count ($products);  for ($i =0; $i <count ($products), $i + +) {for    ($j =0; $j <count ($products [$i]); $j + +) {      echo ' | '. $products [$i] [$j];    }    echo "|<br/>";  }  /   * * | Apple |6|28.8|   * | pork |2|18.8|   * | Biscuit |4|48.8|   * **/?>

demo16.php

<?php  //Create a single array  $products = Array (    ' product ' = ' apple ', ' quantity ' = ' 6 ', ' price ' = ' 28.8 '),    array (' product ' = ' pork ', ' quantity ' = ' 3 ', ' price ' = ' ' 25.8 '),    Array (' product ' = ' cookie ', ' quantity ' = ' 2 ', ' price ' = ' 26.8 ')  );  Print_r ($products);//For  ($i =0; $i <count ($products); $i + +) {//   foreach ($products [$i] as $key = $ Value) {//     echo $key. '--'. $value. ' | '; /   }//   echo ' <br/> ';/} for  ($i =0; $i <count ($products); $i + +) {while    (!! List ($key, $value) =each ($products [$i]) {      echo $key. '--'. $value. ' | ';    }    Echo ' <br/> ';  }  /**   * Products-Apple | Quantity--6| price--28.8|   * Products-Pork | Quantity--3| price--25.8|   * Products-Biscuits | Quantity--2| price--26.8|   * */?>

demo17.php

<?php////sort--array sort//$fruit = array (' banner ', ' Orange ', ' apple '),///////////print_r ($fruit) in order of the key before sorting ;////Sort ($fruit);//Print_r ($fruit);  $numbers = Array (45,44,27,574,241,7,45,1,5,2,4,5);  Print_r ($numbers);  Rsort ($numbers);  Echo ' <br/> ';  Print_r ($numbers);  According to the number, to see the overall number size, according to the string, only the first bit size//$numbers = Array (2,12,3);//Sort ($numbers, sort_numeric);//Print_r ($numbers); Array ([0] = 2 [1] = 3 [2] = +)//$numbers = Array (2,12,3);//Sort ($numbers, sort_string);//Print_r ($number s);//array ([0] = [1] = 2 [2] = 3)?>

demo18.php

<?php//asort-Sorts the array and keeps the index relationship  $fruit = array (' banner ', ' Orange ', ' apple ');//Sort ($fruit);//Print_r ($fruit);  Array ([0] = Apple [1] = banner [2] = orange)  asort ($fruit);  Print_r ($fruit);  Array ([2] = Apple [0] = banner [1] = orange)?>

demo19.php

<?php  $fruit = Array (' b ' = = ' banner ', ' o ' = ' orange ', ' a ' = ' + ' apple ');  Ksort-the array is sorted by key name  Ksort ($fruit)  ;  Print_r ($fruit);  Array ([A] = Apple [b] = banner [o] = orange)?>

demo20.php

<?php  //echo '  ';  Create an array  $pic = Array (' mm1.jpg ', ' mm2.jpg ', ' mm3.jpg ', ' mm4.jpg ', ' mm5.jpg ');  The array is randomly disturbed  //shuffle ($pic);  Most groups are reversed, and a function preceded by an array typically creates a new array  $a = Array_reverse ($pic);  for ($i =0; $i <3; $i + +) {    echo '  ';    echo "\ n";  }? >

demo21.php

<?php  $userName = Array (' Zhang San ');  Print_r ($userName);  The return value of this function will be given, the number of elements of the current array  //array_unshift--insert one or more cells at the beginning of the array  //Insert data at the beginning  array_unshift ($userName, ' John Doe ')  ;  Insert data at the end  Array_push ($userName, ' Wu ');  Delete the beginning element  Array_shift ($userName);  Delete the end of the element  Array_pop ($userName);  Print_r ($userName);? >

demo22.php

<?php  $fruit = array (' banner ', ' Orange ', ' apple ');  This function is used to get the key in an array (key)  //The second parameter indicates that a few//$a = Array_rand ($fruit, 1);//Echo $fruit [$a];  $a = Array_rand ($fruit, 2);  echo $fruit [$a [0]]. ' '. $fruit [$a [1]];? >

demo23.php

<?php  $username = Array (' world ' = ' and ' he ', ' blood ' = ' Zhao blood ', ' learn ' and ' Mo Xue ');  By default, the pointer is in the first Data  //Gets the current element of the pointer, and currently does not move the pointer to the next//Echo present ($username);//echo $username;//Echo Current ($username);//Echo Next ($username);//Echo current ($username)//Echo Next ($username);//Echo Current ($ username);////reset--Points the internal pointer of the array to the first unit//echo Reset ($username);//Echo sizeof ($username);//count  $numbers = Array ( 1,4,5,656,7,5,7,4,7,4,5,7);  Array_count_values--The number of occurrences of all values in the statistic array  print_r (Array_count_values ($numbers));? >

demo24.php

<?php  $a = $b = $c = ";  $fruits = Array (' a ' = = ' Apple ', ' b ' = ' banner ', ' c ' = ' orange ');  The string key (key) is set to a variable by a scalar function, and the value is assigned to the variable  extract ($fruits);  echo $a;  echo $c;  echo $b;  Appleorangebanner?>

I hope this article is helpful to you in PHP programming.