對一個數組(每項都是數值)求和,有哪些方法?
阿新 • • 發佈:2019-02-17
var numbers = []; for (var i = 1; i <= 100; numbers.push(i++)); /** * method 1 */ function addNum01(numArray) { var sum = 0; numArray.forEach(function (e) { sum += e; }); return sum; } /** * method 2 */ function addNum02(numArray) { return numArray.reduce(function (p1, p2) { return p1 + p2; }) } /** * method 3 */ function addNum03(numArray) { var sum = 0; for (var i = 0; i < numArray.length; sum += numArray[i++]); return sum; } function addNum04(numArray) { var sum = 0; for (var i in numArray){ sum += numArray[i]; } return sum; } console.log(addNum01(numbers) + "\t01"); console.log(addNum02(numbers) + "\t02"); console.log(addNum03(numbers) + "\t03"); console.log(addNum04(numbers) + "\t04");