标签：etc oid seq str 1.5 retrieve ngui ring types
Number: For example the price of a product. Whole numbers and non-whole numbers are not distinguished; there is only a single number type. So for example 3/2 will be always 1.5, and never 1. Just like if you are using a calculator.
整数和非整数不区分，只有一个数类型。例如，3/2总是1.5，从不1。就像你在使用计算器一样。
Hash: Associates a unique lookup name with each of its sub variables. The name is an unrestricted string. A hash doesn‘t define an ordering for the sub variables in it. That is, there is no such thing as the first subvariable, and the second subvariable, etc.; the variables are just accessed by name.
通过名字与每个子变量关联。
Sequence: Associates an integer number with each of its sub variables. The first subvariable is associated with 0, the second with 1, the third to 2, and so on; the sub variables are ordered. These numbers are often called the indexes of the sub variables. Sequences are usually dense, i.e., all indexes up to the index of the last subvariable have an associated subvariable, but it‘s not strictly necessary. The type of the subvariable values need not be the same.
通过index与每个子变量关联(从0开始)。
Collection: A collection, from the viewpoint of the template author, is a restricted sequence. You cannot access its size or retrieve its sub variables by index, but they can be still listed with the list directive.
可以通过list指令遍历，但是不能通过index访问。
标签：etc oid seq str 1.5 retrieve ngui ring types
原文地址：http://www.cnblogs.com/rocker-pg/p/7742224.html
