❓ CHALLENGE

```

const arr = ['a', 'b', 'c'];
arr[-1] = 'd';
console.log(arr.length);
```

❓ CHALLENGE

```

var x = 1;
console.log(x+++x);
```

❓ CHALLENGE

```

var x = 1;
if (function f() {}) {
x += typeof f;
}
console.log(x);
```

✌️ A Proposal to Add Signals to JavaScript

A (very) early stage proposal for bringing a new feature to ECMAScript/JavaScript: signals! The proposal brings aboard ideas from a swathe of popular frameworks and aims to align everyone and get us on the same page when it comes to working with state and making updates based upon changes to state. Rob writes more about the proposal here.

ROB EISENBERG AND DANIEL EHRENBERG