Note that this does prevent extensions, but will only throw in strict
mode. In sloppy mode, the assignment will silently fail.
On 18.03.2016 15:07, Michael Theriot wrote:
You can accomplish this by calling `Object.seal(this)` in the constructor.
```js
constructor() {
this.x = 1;
Object.seal(this);
}
```
On Fri, Mar 18, 2016 at 8:36 AM, Brian Barnes <[email protected]
<mailto:[email protected]>> wrote:
I know properties on classes are getting a look over for the next
iteration (last I checked) and I understand javascript is
obviously a different language then other oo languages with a
different foundation, but I bring this up for it's usage in
producing stricter code that reduces errors and is easier to
analyze. A vote for this if anybody considered it!
class Test
{
constructor()
{
this.x=1;
}
func1()
{
this.y=2;
}
func2()
{
console.log(this.x+','+this.y);
}
}
var test1=new Test();
test1.func1();
test2.func2(); // outputs 1,2
var test2=new Test();
test2.func(); // outputs 1,undefined
I know classes contents are meant to be in strict mode, and I
thinking that only allowing properties to be created in the
constructor (or eventually static properties on the class itself)
would make a system less prone to the conditions like you see
above. Basically, func1() would produce a error when run.
I can see why this type of initialization of properties could be
desired, though, especially as it reflect the way it would have
worked if you used a function instead of a class.
[>] Brian
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