[英]How to correctly populate an associative array dynamically in Javascript
I am trying to build arrays within an array and I would like to be able to access the stored data through array[x][y]. 我正在尝试在数组中构建数组,我希望能够通过array [x] [y]访问存储的数据。 I have a sample code below that I can't get to work the way I want and I wonder if anyone can spot the problem.
我下面有一个示例代码,我无法按自己的方式工作,我想知道是否有人可以发现问题。
$.getJSON("/data/", function(data){
var test = {};
var levels = [1,2,3];
$.each(data, function(key, value){
var cat = data[key];
$.each(levels, function(li,l){
var base = cat[2];
var keys = Object.keys(base);
if (l == 1) {
test[l] = {};
$.each(keys, function(ki,k){
test[l][k] = base[k][0];
});
}
});
});
alert(Object.keys(test[1]));
});
The structure of the fetched JSON data is as shown here: 提取的JSON数据的结构如下所示:
{
"1": ["Distribution", 0,
{
"9": ["Salmonella", 0,
{}],
"6": ["E. coli", 0,
{
"8": ["from pigs", 0,
{}],
"7": ["from humans", 0,
{}]}]}],
"2": ["Adhesin", 0,
{
"1": ["PapG", 1,
{
"2": ["has three subtypes:", 0,
{
"3": ["PapG-I", 0,
{}],
"4": ["PapG-II", 0,
{}],
"5": ["PapG-III", 0,
{}]}]}]}],
"3": ["Receptors", 0,
{}],
"4": ["Disease associations", 0,
{}],
"5": ["Regulation", 0,
{}]
}
The code above doesn't seem to store values to the array within the test array as alert(Object.keys(test[1]))
doesn't give anything (ie just blank alert). 上面的代码似乎没有将值存储到测试数组中的数组中,因为
alert(Object.keys(test[1]))
并没有给出任何结果(即只是空白警报)。
Edit: after the mistakes spotted by Oleg V. Volkov (below): 编辑:在Oleg V. Volkov(如下)发现的错误之后:
$.getJSON("/data/", function(data){
var test = {};
var levels = [1,2,3];
$.each(data, function(key, value){
// var cat = data[key];
$.each(levels, function(li,l){
var base = value[2];
var keys = Object.keys(base);
if (l == 1) {
if ($.inArray(l,test) == -1){
test[l] = {};
}
$.each(keys, function(ki,k){
test[l][k] = base[k][0];
});
}
});
});
alert(Object.keys(test[1]));
});
Still not working. 还是行不通。
var cat = data[key];
You don't need this line. 您不需要此行。 Your data is already in
value
. 您的数据已经
value
。
You're overwriting same test[l]
values on each iteration, so in the end you will only have result of the last outermost iteration in it - in many browsers that will be one that goes over "5": ["Regulation", 0, {}]
key/value pair. 您在每次迭代中都覆盖了相同的
test[l]
值,因此最后您只能得到最后一次最外层迭代的结果-在许多浏览器中,它们将超过"5": ["Regulation", 0, {}]
键/值对。 Quick look over you code suggest cat[2]
will be {}
for it and that so last iteration will overwrite anything in test[]
with empty objects. 快速查看您的代码,建议
cat[2]
适用于{}
,因此最后一次迭代将用空对象覆盖test[]
所有内容。 So your keys
correctly returns empty list, but you have an error in your logic. 因此,您的
keys
正确返回了空列表,但是逻辑上有错误。
Regarding your updated example: You're still overwriting test entries with {}
because you use .inArray
to check it and it will always succeed in not finding any number value in array. 关于更新后的示例:您仍在使用
{}
覆盖测试条目,因为使用.inArray
进行了检查,并且在数组中找不到任何数字值总是成功的。 .inArray
looks for a specific value, not keys/indexes. .inArray
查找特定值,而不是键/索引。 You should check if specific index is empty instead with if(!test[l])
您应该使用
if(!test[l])
检查特定索引是否为空if(!test[l])
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