How can I do this using Reduce function? [closed]

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Closed 3 years ago.

var ｙ= '110001'.split("").reverse();
var sum = 0;
for (var i = 0; i < y.length; i++) {
  sum += (y[i] * Math.pow(2, i));
}
console.log(sum);

回答1:

It would be simplest to do

console.log(Array.from('110001').reduce((prev, cur) => prev << 1 | cur));

<< is the left-bitshift operator, which here essentially multiplies by two.

Array.from (if available) is preferable to split. In this case it doesn't matter, but split will fail with surrogate pair characters such as 🍺, while Array.from will handle them correctly. This could also be written as [...'110001'], which ends up being the same thing.

Of course, you could also just say

parseInt('110001', 2)

回答2:

check this snippet

var binary = '110001'.split("").reverse();

var sum = binary.reduce(function(previous, current, index) {
  previous = previous + (current * Math.pow(2, index));
  return previous;
}, 0);

console.log(sum);

Hope it helps

来源：https://stackoverflow.com/questions/40944740/how-can-i-do-this-using-reduce-function