PHP array (previous) traversal

PHP array (previous) traversal

 Demo = array (0 => 'apple', 1 => 'Orange ', 2 => 'bana'); * 2, associated array: key-value form * 3, multi-dimensional array: array $ demo = array (), array (); * // ** array traversal * 1, for * this method is not preferred * array must be a subscript continuous index array ** 2, foreach * foreach ($ arr as $ item ){...} * foreach ($ arr as $ key => $ val ){...} ** 3, while () list () each () combination * each (): an array is required as the parameter, and array (, $ key, $ val) is returned ), is a cursor operation. after execution, false * list (): a, list () = array () is returned. the array must be assigned to list () * B, the number of elements in the array must be the same as the number of parameters in the list () function * c. each element in the array is assigned to each parameter * d, list () in list () only the index array ** e can be accepted, and the internal pointer control function ** prev ($ arr) is traversed in the subscript order of the index: the previous pointer * next ($ arr ): next pointer * reset ($ arr): First * end ($ arr): Last ** current ($ arr): current key * key ($ arr ): current value ** // forecho "\ n... \ 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... \ 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); 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"; prev ($ user); echo current ($ user ). '----------> '. key ($ user ). "\ n";/** result *... apple orange banana... apple orange banana foreach... apple orange banana foreach... 0 => apple 1 => orange 2 => banana ------------------------------------------ while... id --> 1 name --> jack age --> 10 sex --> male sex id -----> 1 name -----> jack age -----> 10 sex -----> male sex age -----> 10 sex -----> male1 ----------> idmale ----------> sex10 ----------> age */