JavaScript:减少麻烦

Question

我正在尝试获取较大组中一个数组的总和。代码更新第一个数组中的第一个数组值，但 reduce 函数不起作用。这是代码:

JavaScript(查看结果的 HTML):

var boughtRaw = [[0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0]];

var boughtCalc = function (level) {
    boughtRaw[0[0]] = 5
    var Raw = boughtRaw[level];
    window["boughtList" + level] = Raw.reduce(function(a, b) {
    return a + b;}, 0);
  };
 
boughtCalc(0);  
document.getElementById("debug").innerHTML = boughtList0;
  /* Should return 5 */

<span id="debug" style="border: 1px dashed red">Debug</span>

Answer 1

您必须将 boughtRaw[0[0]] = 5 更正为此行 boughtRaw[0][0] = 5。

var boughtRaw = [[0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0]];

var boughtCalc = function (level) {
    boughtRaw[0][0] = 5; // corrected
    var Raw = boughtRaw[level];
    window["boughtList" + level] = Raw.reduce(function(a, b) {
    return a + b;}, 0);
  };
 
boughtCalc(0);  
document.getElementById("debug").innerHTML = boughtList0;
/* return 5 */

<span id="debug" style="border: 1px dashed red">Debug</span>

---

要访问数组(数组的...数组的)元素，您必须将[]...[]彼此相邻放置，而不是像这样[[...[]]]。

var element1 = array[0] // get first element of array
var element2 = element1[0] // get first element of element1 
.....
var result = elementN[0] // get first element of elementN

这可以替换为

var result = array[0][0]...[0].