Swift If… Else语句

if boolean_expression {
   /* statement(s) will execute if the boolean expression is true */

} else {
   /* statement(s) will execute if the boolean expression is false */
}

var varA:Int = 100;

/* Check the boolean condition using if statement */
if varA < 20 {
   /* If condition is true then print the following */
   print("varA is less than 20");

} else {
   /* If condition is false then print the following */
   print("varA is not less than 20");
}

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

varA is not less than 20
Value of variable varA is 100