原理是：一個(gè)數(shù)異或同一個(gè)數(shù)兩次，結(jié)果還是那個(gè)數(shù)
int x =5,y=10; //定義兩個(gè)變量
x = x^y;
y = x^y; //y=(x^y)^y
x = x^y; //x=(x^y)^x
x ^= y;
==> y ^= x; ==> x ^= y ^= x ^= y;
x ^= y;
swift 交換方法可以這樣
var a = "123"
var b = "abc"
print(a,b)
(a,b) = (b,a)
print(a,b)
QQ20170531-204644@2x.png
