Php array function example tutorial

Php array function example tutorial

$ Arr = array ("name" => "user1", "age" => "30", "sex" => "man "); Foreach ($ arr as $ key => $ val ){ $ Keys [] = $ key; $ Vals [] = $ val; } Echo" "; print_r($keys); echo " "; Echo ""; Echo" "; print_r($vals); echo " "; ?> 2. use of array_values $ Arr = array ("name" => "user1", "age" => "30", "sex" => "man "); $ Keys = array_values ($ arr ); Echo" "; print_r($keys); echo " "; ?> Array_values (); // obtain the value array_keys () in the array; // Obtain the Jian in_array () in the array; // check whether a value is in the array array_key_exists (); // check whether a key is in the array array_flip (); // the key and value pairs are called array_reverse (); the values in the array are reversed. Counts the elements and uniqueness of the array. count (); 2. array_count_values (); // counts the number of occurrences of each value in the array. 3. array_unique (); // delete the function that uses the callback function to process the array repeatedly: 1. array_filter (); $ Arr = array ("user1" => ); Function older ($ var ){ Return ($ var> 60 ); } $ Arr2 = array_filter ($ arr, "older "); Echo" "; print_r($arr2); echo " "; ?> 2. array_map (); reference parameter: Requirement: Array Value auto-Increment 1 Function show (& $ arr ){ Foreach ($ arr as $ key => $ val ){ $ Arr [$ key] = $ val + 1; } } Array sorting function 1. sort (); ascending, key2.rsort (); descending, key3.asort (); ascending, key4.arsort (); descending, key5.ksort (); sort keys in ascending order. krsort (); sort by key in descending order 7. natsort (); Natural numbers sort ascending order, ratio piece img2.jpg 8. natcasesort (); ignore case-insensitive ascending order 9. multisort (); Multi-array sorting ksort (); $ Arr = array ("user1" => 10, "B" => 1, "c" => 3, "d" => 30 ); $ Arr2 = array_flip ($ arr ); Ksort ($ arr2 ); Echo" "; print_r($arr2); echo " "; ?> Natsort (); $ Array1 = $ array2 = array ("img12.png", "img10.png", "img2.png", "img1.png "); Sort ($ array1 ); Echo "Standard sorting \ n "; Print_r ($ array1 ); Natsort ($ array2 ); Echo "\ nNatural order sorting \ n "; Print_r ($ array2 ); ?> Multi-array sorting: $ Arr = array ("aaa", "bbbbbbbbbbb", "cc", "ddddd "); // Requirement: // 1. Sort by title length // 2. the title length is changed to the key of the title string // Extract the length of the value in the array and use it as a new array // Strlen ($ val) retrieves the string length Foreach ($ arr as $ val ){ $ Lens [] = strlen ($ val ); } Array_multisort ($ lens, SORT_ASC, $ arr); // sorts the array. sort the second array by the first array. SORT_ASC indicates ascending sorting. Sort ($ lens ); $ Arr2 = array_combine ($ lens, $ arr); // The first array acts as the key corresponding to the second array and returns a new array Echo" "; print_r($arr2); echo " "; ?> Splitting, merging, splitting, and combining functions 1. explode (); 2. inplode (); // join (); 3. array_slice (); array truncation 4. array_splice (); array cropping 5. array-merge (); merge multiple arrays 6. array_combine (); merges two arrays. the first array is used as the key, and the last array is used as the value7.array _ intersect (). 8. array_diff (); find the differences between the two arrays, according to the first parameter 9. array_pop (); the last value is displayed, and 10 is returned. array_push (); press a value from the last position and return 11 elements. array_shift (); delete a value 12 from the position before the wash. array_unshift (); press a value from the beginning $ Str = "php, js, html, ces, p "; $ Arr = explode (",", $ str ); Echo" "; print_r($arr); echo " "; ?> 2. inplode (); combines the array into a string $ Str = "php, js, html, ces, p "; $ Arr = explode (",", $ str ); $ Str2 = implode ("-", $ arr ); Echo" "; print_r($str2); echo " "; ?> $ Str = "php, js, html, ces, p "; $ Arr = explode (",", $ str ); $ Arr2 = array_reverse ($ arr); // sort the values in the array in reverse order. $ Str2 = implode ("-", $ arr2 ); Echo" "; print_r($str2); echo " "; ?> Array_slice (); // The screenshot is always taken from the back. $ Arr = array ("aa", "bb", "cc", "dd", "ee", "ff", "gg "); $ Arr2 = array_slice ($ arr,); // Two aa bb instances are intercepted from 0. $ Arr3 = array_slice ($ arr,-3, 2); // This parameter indicates that two requests are intercepted from the last three places to the last three places. // ee ff Echo" "; print_r($arr3); echo " "; ?> Not only can be removed, but can also be added $ Arr = array ("aa", "bb", "cc", "dd", "ee", "ff", "gg "); $ Arr2 = array_splice ($ arr, 0, 3, array ("hh", "ii", "jj", "kk ")); // directly retrieve the value of the original array and change the original array. the original array is the value left after the original array is removed. Echo" "; print_r($arr2); echo " "; Echo" "; print_r($arr); echo " "; ?> Array_merge (); $ A = array ("aa", "bb", "cc "); $ B = array ("dd", "ee", "ff", "gg "); $ Arr = array_merge ($ a, $ B ); Echo" "; print_r($arr); echo " "; ?> Other useful array processing functions: 1. array_rand (); // A random key2.range (); // retrieves an array of a certain range. 3. shuffle (); // disrupt the function of array 4. array_sum (); // calculate the sum of all people in the array (total score). If the sum of keys in the array is calculated, array_flip () can be used to check the health and value of the array, then we can calculate the sum of keys. $ Arr = array ("aa", "bb", "cc", "dd", "ee", "ff", "gg "); // Randomly disrupt the original array order Shuffle ($ arr ); // Retrieve the first three of the arrays $ Arr2 = array_slice ($ arr, 0, 3 ); Echo" "; print_r($arr2); echo " "; ?> // Outputs a four-character verification code at random: // Retrieve the array of 1-9 a-z A-Z $ A = range (1, 9 ); $ B = range (a, z ); $ C = range (A, Z ); // Combine the three numbers and $ D = array_merge ($ a, $ B, $ c ); // Disrupt the merged array Shuffle ($ d ); // Obtain the first 4 digits after merging $ E = array_slice ($ d, 0, 4 ); // Convert the $ e array into a string $ F = join ("", $ e ); Echo $ f; ?>