int has_index(string haystack, int index) int has_index(array haystack, int index) int has_index(mapping|multiset|object|program haystack, mixed index)
Description
Search for index in haystack .
Returns
Returns 1 if index is in the index domain of haystack ,
or 0 (zero) if not found.
This function is equivalent to (but sometimes faster than):
search(indices(haystack), index) != -1
Note
A negative index in strings and arrays as recognized by the
index operators `[]() and `[]=() is not considered
a proper index by has_index()