js数组求和

for (let i = 0; i < array.length; i++) {

    sum += array[i];

}

var sum = 0;

console.time();

sum = eval(arr.join("+"));

console.timeEnd();

console.log(sum);

function sum(arr){

    var result = 0;

    arr.forEach(function(arr) {

        result+= arr;

    });

    return result;

}

function sum(arr) {

  return arr.reduce(function(prev, curr, idx, arr){

    return prev + curr;

  });

}