WoW:API next: Difference between revisions

Allows a program to traverse all fields of a table. Its first argument is a table and its second argument is an index in this table. <b><tt>next</tt></b> returns the next index of the table and the value associated with the index. When called with nil as its second argument, <b><tt>next</tt></b> returns the first index of the table and its associated value. When called with the last index, or with nil in an empty table, <b><tt>next</tt></b> returns nil. If the second argument is absent, then it is interpreted as nil.

Lua has no declaration of fields; There is no difference between a field not present in a table or a field with value nil. Therefore, <b><tt>next</tt></b> only considers fields with non-nil values. The order in which the indices are enumerated is not specified, even for numeric indices. (To traverse a table in numeric order, use a numerical for or the <b><tt>ipairs</tt></b> function.)

The behavior of <b><tt>next</tt></b> is undefined if, during the traversal, you assign any value to a non-existent field in the table. Changing values of existing keys or removing keys is alright though.