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In ES6, how do we quickly get the element?
in MDN Syntax for Set, I didn't find an answer for it.
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Passing a parameter 'n' will return the first 'n' elements of the array. ES6 Version: var first = (array, n) => { if (array == null) return void 0; if (n == null) return array[0]; if (n < 0) return []; return array. slice(0, n); }; console.
Use object. keys(objectName) method to get access to all the keys of object. Now, we can use indexing like Object. keys(objectName)[0] to get the key of first element of object.
To get the first 2 elements of an array, call the slice method passing it a start index of 0 and an end index of 2 as parameters. The slice method will return a new array containing the first 2 elements of the original array.
They don't seem to expose the List to be accesible from the instanced Object. This is from the EcmaScript Draft:
23.2.4 Properties of Set Instances
Set instances are ordinary objects that inherit properties from the Set prototype. Set instances also have a [[SetData]] internal slot.
[[SetData]] is the list of Values the Set is holding.
A possible solution (an a somewhat expensive one) is to grab an iterator and then call next() for the first value:
var x = new Set(); x.add(1); x.add({ a: 2 }); //get iterator: var it = x.values(); //get first entry: var first = it.next(); //get value out of the iterator entry: var value = first.value; console.log(value); //1 Worth mention too that:
Set.prototype.values === Set.prototype.keys If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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