1. 程式人生 > >對一個數組(每項都是數值)求和,有哪些方法?

對一個數組(每項都是數值)求和,有哪些方法?

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");