I know that .slice() can only work on arrays and strings. I'm calling .slice() on an array and I am still getting that error. Here is my code:
var subsets = function(nums) {
let subsets = [];
subsets.push([]);
for(let i = 0; i < nums.length; i++) {
let currentNumber = nums[i];
for(let j = 0; j < subsets.length; j++) {
let currentSubset = subsets[j].slice(0);
let set1 = currentSubset.push(currentNumber);
subsets.push(set1)
}
}
return subsets;
};
Now on the other hand, this works fine if I insert it into the for loop.
const set1 = subsets[j].slice(0); // clone the permutation
set1.push(currentNumber);
subsets.push(set1);Array.prototype.push returns a number, the new length of the array.
Per MDN:
Return value
The new length property of the object upon which the method was called.
When you subsets.push(set1), you push a number, and numbers don't have .slice.
You should do subsets.push(currentSubset) instead.
let set1 = currentSubset.push(currentNumber);
subsets.push(set1)
Here currentSubset.push() will return lenth of new array and which you store in subsets array. And that you have declared array of array.
So in next iteration subsets[1] will be length of array which you stored from set1 not an array.
So I guess you missed some logic over there.