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Tag: arrays

check that a word is an isogram with pure javascript

How do i check that a given word is an isogram with pure javascript, using a function. the function must return true or false. An isogram is a word with a repeated character. I know this code works, but i need a better solution. Answer Here is a simple approach using .split() and .every(): Docs: String.protot…

Getting first element of Observer Array

Hi dear friends, i cannot get first element or data etc. I did try notes[0] but the result was ‘undefined’. What kind of array is this? First time i’ve seen and i am using Vue.Js Answer You can access the first element simply using Array.from: Also, {__ob__: Observer} is a special property a…

Merging Javascript arrays without concat

I have two arrays that I need to combine. Most of the advice on combining arrays I can find use concat. But I don’t want to add to the end of an array, I need to add a key/value pair from array1 to each object in array2. I need to merge this array1: With this array2: In a new combined

Map and Filter to populate array with objects by id

I need to populate array of ids with objects. In other words I have. Array of ids: And array of objects: Either you can sort array of objects based on ids… Or map array of ids to array of objects. Probably I’d prefer the second option. But my approach just doesn’t work The result shall be: o…

Dropdown with multiple selection limit

I relatively new to React and Semantic UI as well. There is a component called Dropdown with a props multiple and selection, which allows to select multiple items. On the output my state looks like this: How can I do setup limit of N amount of elements? Many thanks Answer Well according to https://react.seman…

Convert object to an array of objects?

I have an object that looks like this: and I need to convert it to an array of objects that would look like this: What would be the cleanest & efficient way to do this? Answer You can use .map() with Object.keys(): Useful Resources: Array.prototype.map() Object.keys()

Why does [][[]] evaluate to undefined?

The expression [][[]] evaluates to undefined in JavaScript. My understanding of this was that the compiler sees the second set of […] and interprets that to be an array subscript operator (because you can’t have two arrays next to each other). So the compiler knows that the inner expression, [], m…