Question

对于看起来像这样的JSON对象：

[{
    "gemeente": "amsterdam",
    "stadsdeel": "centrum",
    "adres": "damrak 28-30",
    "bvo": "2000",
},
{
    "gemeente": "amsterdam",
    "stadsdeel": "centrum",
    "adres": "damrak 66",
    "bvo": "1500",
    "": ""
}]

我正在尝试获得bvo值的总和。在这种情况下输出将是3500.然后我需要使用此数字进行数据可视化。我正在d3.js工作，但任何Javascript解决方案都可以。

Answer 1

D3使用d3.sum很好地处理了这个问题，没有经过适当的测试我认为语法应该类似于

d3.sum(list, function(d) { return d.bvo; });

Answer 2

您需要的是

var list = [{
    "gemeente": "amsterdam",
    "stadsdeel": "centrum",
    "adres": "damrak 28-30",
    "bvo": "2000",
},
{
    "gemeente": "amsterdam",
    "stadsdeel": "centrum",
    "adres": "damrak 66",
    "bvo": "1500",
    "": ""
}];

// code to sum the values
var sum = 0;
for(var len = list.length, i=0; i < len; i++){ // for each object in the list
    var item = list[i]; 
    sum += parseInt(item.bvo, 10); // parse its "bvo" element as integer and add it to the sum
}

// output to console the sum.. or do whatever you want with the sum here..
console.log(sum);

Answer 3

我通过常规Javascript得到答案：

var SumByTipe = {};
for (i in data) {
    var currtipe = data[i].tipe;
    if (currtipe in SumByTipe) {
        for (j in data[i]) {
            if (j != "tipe" && j != "mc") {
                SumByTipe[currtipe][j + '_total'] += parseFloat(data[i][j]);
            }
        }
    }
    else {
        var firstSum = {};
        for (j in data[i]) {
            if (j != "tipe" && j != "mc"){
                firstSum[j + '_total'] = parseFloat(data[i][j]);
            }
        }
        SumByTipe[currtipe] = firstSum;
    }
}
console.log(SumByTipe);

虽然我并没有真正得到它如何工作，但它运作良好。： - ）

选择特定的JSON密钥值来对其求和

3 个答案: