Lua，表的大小(#table_name 或 table.getn(table_name)，有时返回 0

Question

当#table_name返回非0值时？再说一遍，当 table.getn(table_name) 确实返回非 0 值时？

Answer 1

仔细阅读手册:

2.5.5 - The Length Operator

The length operator is denoted by the unary operator #. The length of a string is its number of bytes (thatis, the usual meaning of string length when each character is onebyte).

The length of a table t is defined to be any integer index nsuch that t[n] is not nil and t[n+1] is nil; moreover, if t[1] is nil,n can be zero. For a regular array, with non-nil values from 1 to agiven n, its length is exactly that n, the index of its last value. Ifthe array has "holes" (that is, nil values between other non-nilvalues), then #t can be any of the indices that directly precedes anil value (that is, it may consider any such nil value as the end ofthe array).