"Destructuring allows you to bind a set of variables to a corresponding set of values anywhere that you can normally bind a value to a single variable" ("Common Lisp the Language").
Questions tagged [destructuring]
1338 questions
78
votes
4 answers
Destructuring assignment in php for objects / associative arrays
In CoffeeScript, Clojure, ES6 and many other languages we have destructuring of objects/maps/etc somewhat like this:
obj = {keyA: 'Hello from A', keyB: 'Hello from B'}
{keyA, keyB} = obj
I've found the list function in php which lets you…
Cotten
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77
votes
3 answers
Destructuring in Node.JS
This recent video claims that EMCAScript 6 destructuring is already partially implemented in Node.JS. I have tried various examples (using v0.10.12 and the --harmony flag), such as
var [a, b] = [1, 2];
and
var {a: a, b: b} = {a: 1, b: 2};
to no…
Randomblue
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votes
1 answer
How to destructure an object with a key containing a hyphen into a variable?
How do I destructure a property from an object where the key contains a hyphen?
Eg:
{
accept-ranges:"bytes",
cache-control:"public, max-age=0",
content-length:"1174",
content-type:"application/json",
date:"Mon, 03 Oct 2016 06:45:03 GMT",
…
Sathish
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73
votes
4 answers
How can I emulate destructuring in C++?
In JavaScript ES6, there is a language feature known as destructuring. It exists across many other languages as well.
In JavaScript ES6, it looks like this:
var animal = {
species: 'dog',
weight: 23,
sound: 'woof'
}
//Destructuring
var…
Trevor Hickey
- 36,288
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71
votes
8 answers
How do I fetch multiple hash values at once?
What is a shorter version of this?:
from = hash.fetch(:from)
to = hash.fetch(:to)
name = hash.fetch(:name)
# etc
Note the fetch, I want to raise an error if the key doesn't exist.
There must be shorter version of it, like:
from, to, name =…
Dmytrii Nagirniak
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70
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3 answers
React - defaultProps vs ES6 default params when destructuring (performances issues)
I just came across a question about React performances when settings default values in one of my stateless functional components.
This component had a defaultProps which defined row: false, but I didn't like it because the defaultProps is at the end…
Vadorequest
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68
votes
4 answers
Split a string straight into variables
I’d like to know if standard JS provides a way of splitting a string straight into a set of variables during their initial declaration. For example in Perl I would use:
my ($a, $b, $c) = split '-', $str;
In Firefox I can write
var [a, b, c] =…
nb5
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votes
16 answers
React JS Error: Invalid attempt to destructure non-iterable instance
I have a sort filter that takes an array to populate the options. Trying to see the option value equal to the text within the array but I get the error within the title:
Invalid attempt to destructure non-iterable instance
I need to pass the text…
Filth
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59
votes
2 answers
How to mix const and let when using object or array destructuring assignment in ES6?
Example :
const foo = {a: "A", b: "B"}
const {a, b} = foo
What if I want b to be a variable using let ?
PhilipGarnero
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53
votes
4 answers
Destructuring object and ignore one of the results
I have:
const section = cloneElement(this.props.children, {
className: this.props.styles.section,
...this.props,
});
Inside this.props, I have a styles property that I don't want to pass to the cloned element.
How can I do?
Fez Vrasta
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52
votes
1 answer
Python assignment destructuring
These three expressions seem to be equivalent:
a,b,c = line.split()
(a,b,c) = line.split()
[a,b,c] = line.split()
Do they compile to the same code?
Which one is more pythonic?
sds
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51
votes
1 answer
Can I pre-declare variables for destructuring assignment of objects?
Background
When I tried destructuring assignment with arrays I was able to pre-declare my variables:
let a, b, c;
let arr = [1, 2, 3, 4, 5];
[a, b, c] = arr;
console.log(a) // logs 1
console.log(b) // logs 2
console.log(c) // logs 3
This went…
Lucy Bain
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50
votes
5 answers
How do I destructure all properties into the current scope/closure in ES2015?
I'd like to do something like this:
const vegetableColors = {corn: 'yellow', peas: 'green'};
const {*} = vegetableColors;
console.log(corn);// yellow
console.log(peas);// green
I can't seem to find or figure out how to do this but I really…
Resist Design
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40
votes
4 answers
ES6 destructuring within a return statement
Is it possible to destructure an object while returning it at the same time.
For example, to change this code:
const mapStateToProps = ({ newItem }) =>{
const { id, name, price } = newItem;
return { id, name, price };
}
To something like…
kfcobrien
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39
votes
2 answers
destructuring assignment default value
I am learning javascript and I got kind of stuck with ES6 syntax while trying to give a default value to a variable when destructuring.
Basically, I am trying to assign a variable giving the value of an object's property to it and if the value is…
Jay Jeong
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