Swift - 嵌套 If 语句

在 Swift 4 中嵌套if-else语句始终是合法的，这意味着您可以在另一个if或else if 语句旁边使用一个if或else if。

句法

嵌套 if语句的语法如下 -

if boolean_expression_1 {
   /* Executes when the boolean expression 1 is true */
   
   if boolean_expression_2 {
      /* Executes when the boolean expression 2 is true */
   }
}

您可以以与嵌套if语句类似的方式嵌套else if...else。

例子

var varA:Int = 100;
var varB:Int = 200;

/* Check the boolean condition using if statement */
if varA == 100 {
   /* If condition is true then print the following */
   print("First condition is satisfied");

   if varB == 200 {
      /* If condition is true then print the following */
      print("Second condition is also satisfied");
   }
}

print("Value of variable varA is \(varA)");
print("Value of variable varB is \(varB)");

当上面的代码被编译并执行时，它会产生以下结果 -

First condition is satisfied
Second condition is also satisfied
Value of variable varA is 100
Value of variable varB is 200