Trick get a new copy of object/array using spread operator #1823

wonderingabout · 2020-03-26T20:49:24Z

A common trick using the spread operator :)
Credit goes to @Dorus for teaching me this trick !

CLAassistant · 2020-03-26T20:49:32Z

All committers have signed the CLA.

leviding · 2020-03-27T00:57:44Z

1-js/06-advanced-functions/02-rest-parameters-spread/article.md

@@ -119,7 +119,7 @@ f(1); // 1
 ```

 As we remember, arrow functions don't have their own `this`. Now we know they don't have the special `arguments` object either.
-````
+```


Should not change this. It corresponds to the symbol on line 107.

indeed, fixed

leviding · 2020-03-27T00:58:20Z

1-js/06-advanced-functions/02-rest-parameters-spread/article.md

@@ -225,6 +225,49 @@ But there's a subtle difference between `Array.from(obj)` and `[...obj]`:
 So, for the task of turning something into an array, `Array.from` tends to be more universal.


+## Get a new copy of an object/array
+
+Remember when we talked about `Object.assign()` 


Line 230 and 231 should be in one line?

generally, github formatting does automatically a word wrap for one skipped line, the purpose was to keep easy to read code in the github editor
the javascript.info may not behave the same way, so i fixed it to one long line

leviding · 2020-03-27T00:58:36Z

1-js/06-advanced-functions/02-rest-parameters-spread/article.md

+## Get a new copy of an object/array
+
+Remember when we talked about `Object.assign()` 
+[in the past](https://javascript.info/symbol#symbols-are-skipped-by-for-in) ?


Suggested change

[in the past](https://javascript.info/symbol#symbols-are-skipped-by-for-in) ?

[in the past](https://javascript.info/symbol#symbols-are-skipped-by-for-in)?

fixed, thanks

leviding · 2020-03-27T00:58:44Z

1-js/06-advanced-functions/02-rest-parameters-spread/article.md

+Remember when we talked about `Object.assign()` 
+[in the past](https://javascript.info/symbol#symbols-are-skipped-by-for-in) ?
+
+It is possible to do the exact same thing with the spread operator !


Suggested change

It is possible to do the exact same thing with the spread operator !

It is possible to do the exact same thing with the spread operator!

fixed, thanks

leviding · 2020-03-27T00:58:54Z

1-js/06-advanced-functions/02-rest-parameters-spread/article.md

+let arrCopy = [...arr]; // spread the array into a list of parameters
+                        // then put the result into a new array
+
+// do the arrays have the exact same contents ?


Suggested change

// do the arrays have the exact same contents ?

// do the arrays have the exact same contents?

fixed, thanks

leviding · 2020-03-27T00:59:01Z

1-js/06-advanced-functions/02-rest-parameters-spread/article.md

+// do the arrays have the exact same contents ?
+alert(JSON.stringify(arr) === JSON.stringify(arrCopy)); // true (same content)
+
+// are the arrays equal (they share the same reference) ?


Suggested change

// are the arrays equal (they share the same reference) ?

// are the arrays equal (they share the same reference)?

fixed, thanks

leviding · 2020-03-27T00:59:42Z

1-js/06-advanced-functions/02-rest-parameters-spread/article.md

+alert(arrCopy) // 1, 2, 3
+```
+
+Note that it is possible to do the exact same to copy 


Line 252 and 253 should be in one line?

same as #1823 (comment)

leviding · 2020-03-27T00:59:55Z

1-js/06-advanced-functions/02-rest-parameters-spread/article.md

+// do the objects have the exact same contents ?
+alert(JSON.stringify(obj) === JSON.stringify(objCopy)); // true (same content)
+
+// are the arrays equal (they share the same reference) ?


Suggested change

// are the arrays equal (they share the same reference) ?

// are the arrays equal (they share the same reference)?

fixed, thanks

leviding · 2020-03-27T01:00:12Z

1-js/06-advanced-functions/02-rest-parameters-spread/article.md

+alert(obj === objCopy); // false (not same reference)
+```
+
+This way of copying an object is much shorter than 


Line 267 and 268 should be in one line?

same as #1823 (comment)

paroche · 2020-03-29T03:38:02Z

Alexey -- is there a specific change you want me to look at? Everything I see above seems to be marked "outdated".

In the a54f242 branch linked to in the last section there is some awkward language:

'Note that it is possible to do the exact same to copy of objects: '

could be improved:

'Note that it is possible to do the exact same thing to copy objects:'

or

'Note that it is possible to do the exact same thing to make a copy of an object:'
(my preference)

Rest of the language is OK.

Anything else?

wonderingabout · 2020-03-29T06:08:24Z

fixed, it's indeed clearer

i removed the unneeded "exact" word :

'Note that it is possible to do the same thing to make a copy of an object:'

paroche · 2020-03-29T06:11:41Z

Fine by me!

wonderingabout · 2020-03-29T06:16:38Z

@paroche did you accidentally hit the close PR instead of the merge PR button (just asking myself 🤔 )

paroche · 2020-03-29T06:19:12Z

You could say that. Anyway, as far as I'm concerned it should be merged (and closed).

paroche · 2020-03-29T06:20:05Z

And it is.

Not sure if it was my place, but if not, it can be undone.

wonderingabout · 2020-03-29T06:25:52Z

yes, you can always @ me if we need to change something

wonderingabout force-pushed the trick-deep-copy-spread branch from 3d6fa69 to a2000fc Compare March 26, 2020 20:56

wonderingabout changed the title ~~Trick deep copy spread~~ Trick get a new copy of object/array using spread operator Mar 26, 2020

wonderingabout force-pushed the trick-deep-copy-spread branch from a2000fc to 9cc9ad2 Compare March 26, 2020 21:24

leviding reviewed Mar 27, 2020

View reviewed changes

wonderingabout force-pushed the trick-deep-copy-spread branch 2 times, most recently from 0c158d9 to a54f242 Compare March 27, 2020 06:51

lex111 requested a review from paroche March 29, 2020 03:00

trick get a new copy of objects/arrays using the spread operator

f4cb058

wonderingabout force-pushed the trick-deep-copy-spread branch from a54f242 to f4cb058 Compare March 29, 2020 06:06

paroche closed this Mar 29, 2020

paroche reopened this Mar 29, 2020

paroche merged commit c038ef4 into javascript-tutorial:master Mar 29, 2020

wonderingabout mentioned this pull request Mar 29, 2020

fix missing js formatting #1830

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Trick get a new copy of object/array using spread operator #1823

Trick get a new copy of object/array using spread operator #1823

wonderingabout commented Mar 26, 2020

CLAassistant commented Mar 26, 2020 •

edited

Loading

leviding Mar 27, 2020

wonderingabout Mar 27, 2020

leviding Mar 27, 2020

wonderingabout Mar 27, 2020

leviding Mar 27, 2020

wonderingabout Mar 27, 2020

leviding Mar 27, 2020

wonderingabout Mar 27, 2020

leviding Mar 27, 2020

wonderingabout Mar 27, 2020

leviding Mar 27, 2020

wonderingabout Mar 27, 2020

leviding Mar 27, 2020

wonderingabout Mar 29, 2020

leviding Mar 27, 2020

wonderingabout Mar 27, 2020

leviding Mar 27, 2020

wonderingabout Mar 27, 2020

paroche commented Mar 29, 2020

wonderingabout commented Mar 29, 2020 •

edited

Loading

paroche commented Mar 29, 2020

wonderingabout commented Mar 29, 2020

paroche commented Mar 29, 2020

paroche commented Mar 29, 2020 •

edited

Loading

wonderingabout commented Mar 29, 2020

	[in the past](https://javascript.info/symbol#symbols-are-skipped-by-for-in) ?
	[in the past](https://javascript.info/symbol#symbols-are-skipped-by-for-in)?

	It is possible to do the exact same thing with the spread operator !
	It is possible to do the exact same thing with the spread operator!

	// do the arrays have the exact same contents ?
	// do the arrays have the exact same contents?

	// are the arrays equal (they share the same reference) ?
	// are the arrays equal (they share the same reference)?

Trick get a new copy of object/array using spread operator #1823

Trick get a new copy of object/array using spread operator #1823

Conversation

wonderingabout commented Mar 26, 2020

CLAassistant commented Mar 26, 2020 • edited Loading

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

paroche commented Mar 29, 2020

wonderingabout commented Mar 29, 2020 • edited Loading

paroche commented Mar 29, 2020

wonderingabout commented Mar 29, 2020

paroche commented Mar 29, 2020

paroche commented Mar 29, 2020 • edited Loading

wonderingabout commented Mar 29, 2020

CLAassistant commented Mar 26, 2020 •

edited

Loading

wonderingabout commented Mar 29, 2020 •

edited

Loading

paroche commented Mar 29, 2020 •

edited

Loading