Question

我有3个如下所示的变量，我希望结果的优先级为return x，如果x为空则返回y，如果x和y都为空则返回z。

下面是我的代码，但这不起作用。

val x = "1"
val y = "2"
val z = "3"

val result = {
var res = "
if (x == "") y else x
else if (y == "") z
}
For result First priority is to x and if x = "" then y, if y also "" then return z

请帮助

Answer 1

您正在将Integer值分配给变量并检查条件是否为空字符串。 Comparing values of types Int and String using `==' will always yield false

请检查以下代码。

// For variables of type string.
if(x != "") x else if (y != "") y else z


scala> val x = 1
x: Int = 1

scala> val y = 2
y: Int = 2

scala> val z = 3
z: Int = 3

scala> if(x != "") x else if (y != "") y else z // This will give result if variables are type string. but if it is int type checking this way give you wrong values.
<console>:30: warning: comparing values of types Int and String using `!=' will always yield true
       if(x != "") x else if (y != "") y else z
            ^
<console>:30: warning: comparing values of types Int and String using `!=' will always yield true
       if(x != "") x else if (y != "") y else z
                                ^
res8: Int = 1


scala> if (!x.isNaN) x else if(!y.isNaN) y else z // Check this way

如何在其他情况下匹配多个条件

1 个答案: