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{{ | {{wowlua}} | ||
Returns the next key/value pair for a given table and key. | Returns the next key/value pair for a given table and key. | ||
key, value = next (table, [oldKey]) | key, value = next (table, [oldKey]) | ||
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. '''<tt>next</tt>''' returns the next index of the table and the value associated with the index. When called with nil as its second argument, '''<tt>next</tt>''' returns the first index of the table and its associated value. When called with the last index, or with nil in an empty table, '''<tt>next</tt>''' returns nil. If the second argument is absent, then it is interpreted as nil. | 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. '''<tt>next</tt>''' returns the next index of the table and the value associated with the index. When called with nil as its second argument, '''<tt>next</tt>''' returns the first index of the table and its associated value. When called with the last index, or with nil in an empty table, '''<tt>next</tt>''' 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, '''<tt>next</tt>''' 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 '''<tt>ipairs</tt>''' function.) | 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, '''<tt>next</tt>''' 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 '''<tt>ipairs</tt>''' function.) | ||
The behavior of '''<tt>next</tt>''' 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. | The behavior of '''<tt>next</tt>''' 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. | ||