PHP Array (prev) traversal

 Demo = Array (0=> ' apple ',1=> ' orange ',2=> ' banana '); * 2, associative array: Key-value form * 3, Multidimensional array: array of arrays $demo = Array (array (), array ()); *//* * Array Traversal * 1, for * This way is not preferred * array must be subscript contiguous indexed array * * 2, foreach * foreach ($arr as $item) {...} * foreach ($ar r as $key = = $val) {...} * * 3, while () list () every () combination * each (): requires an array as a parameter, returns array (0,1, $key, $val), is a cursor operation, executes to the last return False * List (): A, list () = array () needs to be assigned to list () * B, the number of elements in the array is the same as the number of parameters in the list () function * C, each element in the array Assign to each parameter in list () * d, List () can only accept indexed array * E, traverse by index in subscript order * * Array internal pointer control function * * PREV ($arr): Previous reference    Pin * Next ($arr): Next pointer * Reset ($ARR): First * END ($arr): Last * * Current ($arr): currently key * Key ($arr): Current value * *///Forecho "\ n for ... \ n"; $demo = Array (' Apple ', ' orange ', ' banana '); for ($i =0; $i
 
  ' Apple ',1=> ' orange ',2=> ' banana '); for ($i =0; $i
  
   
 $val) {echo '. $key. ' = '. $val. ';} echo "\ n". ' ----------------------------------------'; $user = array (' ID ' =>1, ' name ' = ' Jack ', ' age ' =>10, ' sex ' = '    Male ');//Whileecho "\ n" while ($arr =each ($user)) {//"$arr [0]--> $arr [1]"; echo $arr [' key ']. -". $arr [' value '].";} echo "\ n-------------------------------------------", while (list ($key, $value) =each ($user)) {echo '. $key. '----- > '. $value. ';} echo "\ n-------------------------------------------\ n", Reset ($user), while (List ($key, $value) =each ($user)) {echo ' . $key. '-----> ' $value. ';} echo "\ n-------------------------------------------\ n" while (list ($key, $value) =each ($user)) {echo '. $key. '----- > '. $value. ';} Reset ($user); next ($user); next ($user); echo "\ n-------------------------------------------\ n"; while (List ($key, $ Value) {=each ($user)) {echo '. $key. '-----> ' $value. ';} Reset ($user); echo "\ n"; Echo current ($user). ' ----------> '. Key ($user). " \ n "; end ($user); Echo Current ($USER). ' ----------> '. Key ($user). " \ n ";p rev ($user); Echo current ($user). ' ----------> '. Key ($user). " \ * * * result * for ... apple orange Banana for ... apple orange Banana foreach ... apple orange banana foreach ...  0=>apple 1=>orange 2=>banana----------------------------------------while ... id-->1 name-->jack Age-->10 sex-->  Male--------------------------------------------------------------------------------------ID----->1 Name----->jack Age----->10 Sex----->  Male--------------------------------------------------------------------------------------Age----->10 Sex----->male1---------->idmale---------->sex10---------->age */
  
 

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