如何计算数组中的值数? [英] How to count number of values in array?
问题描述
我正在尝试计算json数组的值.
I am trying to count the values a json array.
如果"beta = b",我想计算"sierra"数据数组中id的数量.因此,请对照设置为值"b"的环境变量("B")检查data [].beta的值.
I want to count the number of id's in the data array of "sierra" if "beta = b". Hence checking the value of data[].beta against the environment variable ("B") set to value 'b'.
这里的问题是我在每次数据迭代中都没有塞拉利昂" [].
The issue here is I do not have "sierra" in every iteration of data[].
{
"data": [{
"alpha": "a",
"beta": "b",
"delta": {
"cat": "dog"
},
"gamma": {
"sierra": {
"data": [
{
"type": "alphabet",
"id": "a"
},
{
"type": "alphabet",
"id": "b"
}
]
}
}
},
{
"alpha": "a",
"beta": "b",
"delta": {
"cat": "dog"
},
"bravo": {
"data": [
{
"type": "number",
"id": "1"
},
{
"type": "number",
"id": "2"
}
]
}
}
},
{
"alpha": "x",
"beta": "y",
"delta": {
"cat": "dog"
},
"gamma": {
"sierra": {
"data": [
{
"type": "alphabet",
"id": "c"
},
{
"type": "alphabet",
"id": "d"
}
]
}
}
}]
}
上面的json是我在邮递员中看到的响应正文. 循环"是我的"for"循环的计数.
Above json is the response body I see in postman. "loop" is the count of my "for" loop.
我已经尝试过了:
1. pm.response.json().data[loop].gamma.sierra.data().id).size()
2. for(var loop =0; loop < pm.response.json().data.length; loop++)
{
if(pm.response.json().data[loop].beta===pm.variables.get("B"))
{
pm.response.json().data.map((item, loop) => {
if(item.gamma){ // check if gamma key is present
console.log(item.gamma.sierra.filter(data =>data.id
).length); //
}
});
result=true;
break;
}
}
pm.expect(true).to.eql(result);
预期:2
Actual: TypeError: Cannot read property 'sierra' of undefined
Actual: item.relationships.apps.filter is not a function
推荐答案
您可以采用动态方法,将要计算特定内部键的对象的键移交.
You could take a dynamic apporach and hand over the key of the object where you like to count a certain inner key.
function count(object, key, subKey) {
const noObject = o => !o || typeof o !== 'object';
function subCount(object) {
if (noObject(object)) return 0;
if (subKey in object) return 1;
return Object.values(object).reduce((s, o) => s + subCount(o), 0);
}
if (noObject(object)) return 0;
if (key in object) return subCount(object[key]);
return Object.values(object).reduce((s, o) => s + count(o, key, subKey), 0);
}
var data = { data: [{ alpha: "a", beta: "b", delta: { cat: "dog" }, gamma: { sierra: { data: [{ type: "alphabet", id: "a" }, { type: "alphabet", id: "b" }] } } }] };
console.log(count(data, 'sierra', 'id')); // 2
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