swift 传值 引用 (=、&)

var a =
1;
var b =
a;
a=2;

println("\(a),\(b)");//2,1

struct cs{

var v:Int =
99;
}
var i =
cs();
var j =
i;
i.v =
98;

println("\(i.v),\(j.v)");//98,99

class ca{

var v:Int;

init(var a:ca){//拷贝构造实现传值

self.v = a.v;
}

init(){

v = 100;
}
}

var x =
ca();
var y =
x;
var z =
ca(a: x);
x.v =
200;

println("\(x.v),\(y.v),\(z.v)");//200,200,100

//Int、struct是copy，class是引用