Nice technique. But it works only with primitives. If you do not mind I want to add a bit more info about this topic. If you need to find duplicates in array of objects, you can do something like this:
function checkForDuplicates(source, keyName) { return source.filter((item, index, array) => { return array.findIndex(t => t[keyName] === item[keyName]) === index; }).length !== source.length }
or use almost the same technique as the author:
function checkForDuplicates(array, keyName) { return new Set(array.map(item => item[keyName])).size !== array.length }
Yep. It is cleaner than mine.
could you please explain this syntax to me and thank you in advance.
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Nice technique. But it works only with primitives.
If you do not mind I want to add a bit more info about this topic.
If you need to find duplicates in array of objects, you can do something like this:
or use almost the same technique as the author:
Yep. It is cleaner than mine.
could you please explain this syntax to me and thank you in advance.