I have a prototype function that changes Boolean `true` to `false` and visa versa.

```
Boolean.prototype.switch = function() {
    return this.toString() === 'false';
};

```

And currently I have to use the following to change the original value.

```
var a = true;
a = a.switch();

```

Is there a way I can change the original variable (`a`) without `a =`? Meaning the script below run the same as above?

```
var a = true;
a.switch();

```

I am creating a quick game, and in the game there are 25 blocks which can have a value of on or off, or as I made it, `true` or `false`. When you click the block it switches values. While I was making the code to switch the values, I became a bit curious to if there is a way to remove `a =` and still change the value.

**Note** I am not asking for help with how to make this prototype function, I am asking if there is a way to change the value without a left hand side in an assignment