defined

语法

defined(names, [type=VAR])

参数

names 可以是字符串标量或向量，表示对象名。

type 可为 VAR（本地变量），SHARED（共享变量）或 DEF（函数定义）。默认值为VAR。

详情

返回一个标量/向量，表示names中的每个元素是否已被定义。

例子

$ x=10
$ y=20
$ def f(a){return a+1}
$ share table(1..3 as x, 4..6 as y) as t1;

$ defined(["x","y","f",`t1]);
[1,1,0,0]

$ defined(["x","y","f",`t1], DEF);
[0,0,1,0]

$ defined(["x","y","f",`t1], SHARED);
[0,0,0,1]