VBA中的链式赋值

Question

与C/CPP/CSharp/JScript一样,我们如何在VBA中进行链式赋值？换句话说,VBA是否具有赋值运算符的右关联性？

例如在C-sharp和JavaScript中,我们可以使用:

var alpha, bravo, charlie;
alpha = bravo = charlie = "hello";

现在在VBA中编写此表达式必须:

Dim alpha, bravo, charlie
alpha = "hello"
bravo = "hello"
charlie = "hello"

但我们不能使用:

Dim alpha, bravo, charlie
alpha = bravo = charlie = "hello"

VBA不允许折叠表达式.还有其他办法吗？

Answer 1

不,VBA与赋值运算符没有正确的关联性.但是,VBA确实具有其他逻辑运算符的右关联性或链接操作.请考虑以下表达式:

alpha = 3
bravo = 5
charlie = 4

alpha = bravo < charlie

MsgBox(alpha) 'would display false

alpha = 3
bravo = 5
charlie = 4

alpha = bravo > charlie < alpha

MsgBox(alpha) 'would display ture .. because (bravo > charlie) is true 
                                      'and true (or 1) less than alpha

但是,VBA解释器优先于赋值运算符的比较运算符,两者都表示为=.以机智,

alpha = bravo = "hello"
MsgBox(alpha) 'would display false, because bravo <> "hello"

因此,您需要明确使用多个语句进行分配.