How to use the entries (), keys () and values () methods in ES6

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Entries (), keys () and values ()

ES6 provides three new methods-- entries (), keys (), and values ()-- for traversing arrays. They all return a traversal object that can be traversed with a for...of loop, except that keys () is the traversal of the key name, values () is the traversal of the key value, and entries () is the traversal of the key-value pair.

For (let index of ['asides,' b'] .keys ()) {console.log (index);} / 0 / / 1 for (let elem of ['asides,' b'] .values ()) {console.log (elem);} / /'a' / /'b' for (let [index, elem] of ['asides,' b'] .values ()) {console.log (index, elem) } / / 0 "a" / / 1 "b"

If you do not use a for...of loop, you can manually call the next method of the traversal object to traverse.

Let letter = ['averse,' baked,'c']; let entries = letter.entries (); console.log (entries.next () .value); / / [0,'a'] console.log (entries.next () .value); / / [1,'b'] console.log (entries.next () .value) / / [2,'c'] these are all the contents of this article entitled "how to use the entries (), keys () and values () methods in ES6". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!