var a:(Int)=20
var b:(Int)=30
func swap(a: inout Int , b:inout Int){
//交换数值
let temp = a
a = b
b = temp
}
var x = 20 , y = 30
swap(a:&x , b:&y)
//打印结果
print(x,y)
Swift例如: 变量a值为20,变量b值为30,调用函数后,a的值变为30,b的值变为20

var a:(Int)=20
var b:(Int)=30
func swap(a: inout Int , b:inout Int){
//交换数值
let temp = a
a = b
b = temp
}
var x = 20 , y = 30
swap(a:&x , b:&y)
//打印结果
print(x,y)