1Procumbens 57 天前
3Nitroethane 57 天前 1
In Objective-C when you declare a property @synthesize would create the getter and setters for you automatically since clang 3.2. So, the default @synthesize for a property "foo" would look like this:
@synthesize foo = _foo
because of that _foo would then be the iVar. In other words you could have done the @synthesize yourself and called the iVar whatever you liked:
@synthesize foo = myiVarFoo
so in this case there is no "_"
So now in Swift from the documentation:
Swift unifies these concepts into a single property declaration. A Swift property does not have a corresponding instance variable, and the backing store for a property is not accessed directly.
So from the documentation it's clear that swift does not have a corresponding instance variable thus no need to have the "_" around anymore.