How do I destructure all properties into the current scope/closure in ES2015?
I think you're looking for:
const {corn, peas} = vegetableColors;
Live on Babel's REPL
If Pointy's right that you're asking how to do this without knowing the names corn
and peas
, you can't with destructuring assignment.
You can at global scope only, using a loop, but I'm sure you don't want to do this at global scope. Still, just in case:
// I'm sure you don't really want this, just being thorough
Object.keys(vegetableColors).forEach((key) => {
Object.defineProperty(this, key, {
value: vegetableColors[key]
});
});
(Throw enumerable: true
on there if you want these pseudo-constants to be enumerable.)
That works at global scope because this
refers to the global object.
I think you're looking for the with
statement, it does exactly what you are asking for:
const vegetableColors = {corn: 'yellow', peas: 'green'};
with (vegetableColors) {
console.log(corn);// yellow
console.log(peas);// green
}
However, it is deprecated (in strict mode, which includes ES6 modules), for good reason.
destructure all properties into the current scope
You cannot in ES61. And that's a good thing. Be explicit about the variables you're introducing:
const {corn, peas} = vegetableColors;
Alternatively, you can extend the global object with Object.assign(global, vegetableColors)
to put them in the global scope, but really, that's worse than a with
statement.
1: … and while I don't know whether there is a draft to allow such things in ES7, I can tell you that any proposal will be nuked by the TC :-)
I wouldn't recommend it, but you can use eval()
to accomplish something similar:
vegetableColors = {corn: 'yellow', peas: 'green'};
function test() {
for ( let i=0; i < Object.keys(vegetableColors).length; i++ ) {
let k = Object.keys(vegetableColors)[i];
eval(`var ${k} = vegetableColors['${k}']`);
}
console.log(corn); // yellow
}
test();
console.log(corn); // undefined (out of scope)