How to concatenate and use spread operator in dart

This is js code of doing it!

 nums = [].concat(...digitBuckets);

how can i implement it in dart?

nums=[].addAll(...digitBucketsd);//facing problem here and confused

The spread operator is designed to insert array elements into another array or to map its elements to function arguments.

The mistake is that: elements of array are used as arguments of concat function, but concat function requires array as argument but not its elements as arguments:

replace

nums = [].concat(...digitBuckets);
nums = [].addAll(...digitBucketsd);

with

nums = [].concat(digitBuckets);
nums = [].addAll(digitBucketsd);

or with spread

nums = [...digitBuckets];
nums = [...digitBucketsd];

also digitBucketsd is present in question instead of digitBuckets