遍历嵌套的 json 对象数组
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Iterate through nested json object array
提问by Saurabh
I have to iterate through json array object.
我必须遍历 json 数组对象。
It has following structure.
它具有以下结构。
var myJSONObject = {
"abc": {
"prod_1": [
{"prod_ver" : "prod 1 ver 1"},
{"prod_ver" : "prod 1 ver 2"},
],
"prod_2": [
{"prod_ver" : "prod 2 ver 1"},
{"prod_ver" : "prod 2 ver 2"},
],
"prod_3": [
{"prod_ver" : "prod 3 ver 1"},
{"prod_ver" : "prod 3 ver 2"},
]
}
};
Basically what I am doing is prod_1 is name of a product and the list of versions that prod_1 has are populated inside it.
基本上我正在做的是 prod_1 是产品的名称，并且 prod_1 具有的版本列表填充在其中。
So now what i want is the name of the product as well as what versions it has.
所以现在我想要的是产品的名称以及它的版本。
The problem is there can be many products and many versions under that product. So i need a proper looping structure in javascriptthat can be generic to handle it.
问题是该产品下可以有许多产品和许多版本。所以我需要一个适当的javascript循环结构，它可以是通用的来处理它。
It would be best if the loop stores product name in one var and it's version in another var as there are some checking i need to on product name.
如果循环将产品名称存储在一个 var 中并将其版本存储在另一个 var 中，那将是最好的，因为我需要对产品名称进行一些检查。
If the json structure is wrong or a better json structure can be written the please suggest a right/better structure.
如果 json 结构错误或可以编写更好的 json 结构，请提出正确/更好的结构。
Please HELP
请帮助
Thanks in advance.
提前致谢。
回答by Korijn
Since myJSONObject.abccontains a list of products it would make more sense to define the property abcas an array. Like this:
由于myJSONObject.abc包含产品列表，将属性定义abc为数组会更有意义。像这样：
var myJSONObject =
{
"abc":
[
[
{"prod_ver" : "prod 1 ver 1"},
{"prod_ver" : "prod 1 ver 2"},
],
[
{"prod_ver" : "prod 2 ver 1"},
{"prod_ver" : "prod 2 ver 2"},
],
[
{"prod_ver" : "prod 3 ver 1"},
{"prod_ver" : "prod 3 ver 2"},
]
]
};
Then you can iterate over the products and their versions using normal loops:
然后您可以使用普通循环迭代产品及其版本：
for(var i = 0; i < myJSONObject.abc.length; i++)
{
var product = myJSONObject.abc[i];
for(var j = 0; j < product.length; j++)
{
var version = product[j];
}
}
You could take it slightly further and alter your JSON object's structure a bit to make it more easily understandable.
您可以更进一步，稍微改变一下 JSON 对象的结构，使其更易于理解。
var catalog =
{
"products": [
{
"name": "prod 1",
"versions": [
"ver 1",
"ver 2"
]
},
{
"name": "prod 2",
"versions": [
"ver 1",
"ver 2"
]
}
]
};
for(var i = 0; i < catalog.products.length; i++)
{
var product = catalog.products[i];
var productName = product.name;
for(var j = 0; j < product.versions.length; j++)
{
var version = product.versions[j];
}
}
回答by T.J. Crowder
myJSONObject.abcis an object with keys like prod_1, prod_2, etc. You can loop through the keys of an object using for-in. So:
myJSONObject.abc是一个带有诸如prod_1、prod_2等键的对象for-in。您可以使用 遍历对象的键。所以：
var productName;
var productVersionArray;
for (productName in myJSONObject.abc) {
productVersionArray = myJSONObject.abc[productName];
}
Note that the order of the keys is not defined by the specification and will vary from JavaScript engine to JavaScript engine. If you want to do them in a particular order, you have to get an array of them, sort it in the order you want, and then loop through that array. (In an ES5-enabled environment, you can get an array of the keys of an object from Object.keys(yourObject). But you'd need a shim for older browsers.)
请注意，规范中未定义键的顺序，并且会因 JavaScript 引擎而异。如果您想按特定顺序执行它们，则必须获取它们的数组，按所需顺序对其进行排序，然后循环遍历该数组。（在启用 ES5 的环境中，您可以从 中获取对象键的数组Object.keys(yourObject)。但是对于旧浏览器，您需要一个垫片。）
Within that loop, you can loop through the array using a standard forloop:
在该循环中，您可以使用标准for循环遍历数组：
for (versionIndex = 0; versionIndex < productVersionArray.length; ++versionIndex) {
// Use `productVersionArray[versionIndex].prod_ver` here
}
Here's an example putting it all together:
这是一个将所有内容放在一起的示例：
(function() {
var myJSONObject =
{
"abc":
{
"prod_1":
[
{"prod_ver" : "prod 1 ver 1"},
{"prod_ver" : "prod 1 ver 2"}
],
"prod_2":
[
{"prod_ver" : "prod 2 ver 1"},
{"prod_ver" : "prod 2 ver 2"}
],
"prod_3":
[
{"prod_ver" : "prod 3 ver 1"},
{"prod_ver" : "prod 3 ver 2"}
]
}
};
var productName;
var productVersionArray;
var versionIndex;
for (productName in myJSONObject.abc) {
productVersionArray = myJSONObject.abc[productName];
display(productName + " has " + productVersionArray.length + " versions listed");
for (versionIndex = 0; versionIndex < productVersionArray.length; ++versionIndex) {
display("* " + productVersionArray[versionIndex].prod_ver);
}
}
function display(msg) {
var p = document.createElement('p');
p.innerHTML = String(msg);
document.body.appendChild(p);
}
})();
回答by Vishwanath
function z() {
for (let key in myJSONObject.abc) {
let value = myJSONObject.abc[key];
for (let i = 0; i <= value.length; i++) {
console.log(value[[i]]);
}
}
}
回答by Lae Kettavong
Updated with ES6
用 ES6 更新
var { products } =
{
"products": [
{
"name": "prod 1",
"versions": [
"ver 1",
"ver 2"
]
},
{
"name": "prod 2",
"versions": [
"ver 1",
"ver 2"
]
},
{
"name": "prod 3",
"versions": [
"ver 1",
"ver 2"
]
}
]
};
let inventory = products.reduce((accumulator, currentValue) => {
let { name, versions } = currentValue;
accumulator[name] = versions
return accumulator
}, []);
Object.entries(inventory).forEach((prod) => {
let prodName = prod[0];
let prodVers = prod[1].join(", ");
});
