Syntax:DsSet public DsMap::keys (void)
Parameter: this function takes no parameters.Return Value:Returns a Ds / Set containing all the keys of the specified Map instance in the same order.Below the programs illustrate the Ds / Map::keys()function in PHP:Program 1:
// PHP program for illustrating the keys() function $map = new DsMap ([1 = > " Geeks " , 2 = > "for" , 3 = > "Geeks" ]); print_r ( $map -> keys());
?> Output:DsSet Object ([0] = > 1 [1] = > 2 [2] = > 3)
Program 2:
// PHP program to illustrate the keys() function $map = new DsMap ([ "first" = > "Geeks" , "second" = > "for" , "third" = > "Gee ks " ]); print_r ( $map -> keys());
?> Output:DsSet Object ([0] = > first [1] = > second [2] = > third)
Link : http://php.net/manual/en/ds-map.keys.php /
