member_array()  -  returns  index of an occurence of a given item in an
array or string

int member_array( mixed item, mixed * | string arr, void | int start );

Returns the index of the first occurence of 'item' in array  'arr',  or
the  first  occurence  at  or after 'start'.  If the item is not found,
then -1 is returned.

Note, if the second argument is a string, the first parameter must be an int
representing the character you are looking for in the provided string.

member_array( "red", ({ "red", "blue", "red", "green", "red", }) ) ;
// 0

member_array( "red", ({ "red", "blue", "red", "green", "red", }) , 1) ;
// 2

member_array( "blue", ({ "red", "blue", "red", "green", "red", }) , 3) ;
// -1

member_array( "purple", ({ "red", "blue", "red", "green", "red", }) ) ;
// -1

member_array('F', "Drink the FluffOS Kool-Aid!") ;
// 10

member_array('Z', "Drink the FluffOS Kool-Aid!") ;
// -1