Check array only contains unique value javascript

You can check if an array contains only unique values in JavaScript by using a Set, which inherently only allows unique values.

Here’s how:

function isUnique(arr) {
    return new Set(arr).size === arr.length;
}

• This function takes an array (arr) as an argument.
• It creates a new Set from the array, which will only contain unique values.
• It checks if the size of the Set is equal to the length of the original array.
• If these values are equal, it means that all values in the array were unique, so the function returns true.
• If they are not equal, it means that some values in the array were not unique, so the function returns false.

For example, calling isUnique([1, 2, 3, 4, 5]) will return true, but calling isUnique([1, 2, 3, 3, 5]) will return false.