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[英]How can I loop through an array of object and get one property element out of the two objects listed inside the array?
[英]How can I pull out two elements of every object in an array of objects and make a new one
我有一个数组,它的长度可以随时> 1,并且会不断变大。
我只需要提取父数组元素的两个值,然后将它们放入新数组中。
这是基本数组的示例:
{
"strains":[
{
"id": 150,
"name": "Animal Cookies (Phat Panda)",
"label": "Animal Cookies (Phat Panda)",
"thcpct": 14,
"cbdpct": 19,
"ttlpct": 33,
"type": "Hybrid SD",
"subtype": "Sativa Dominant",
"bitactive": 1,
"useradded": "jjones",
"dateadded": "4/12/2017"
},
{
"id": 110,
"name": "Blue Dream (Pioneer)",
"label": "Blue Dream (Pioneer)",
"thcpct": 24,
"cbdpct": 0,
"ttlpct": 24,
"type": "Sativa",
"subtype": "None",
"bitactive": 1,
"useradded": "jjones",
"dateadded": "3/27/2017"
},
{
"id": 30,
"name": "Candyland",
"label": "Candyland",
"thcpct": 25,
"cbdpct": 75,
"ttlpct": 100,
"type": "Hybrid SD",
"subtype": "Sativa Dominant",
"bitactive": 1,
"useradded": "jjones",
"dateadded": "1/1/2017"
},
{
"id": 130,
"name": "Dragon OG (Avitas)",
"label": "Dragon OG (Avitas)",
"thcpct": 26,
"cbdpct": 18,
"ttlpct": 44,
"type": "Hybrid SD",
"subtype": "Sativa Dominant",
"bitactive": 1,
"useradded": "jjones",
"dateadded": "4/10/2017"
}
]
}
这是我希望提取后的样子:
{
"strains":[
{
"id": 150,
"label": "Animal Cookies (Phat Panda)",
},
{
"id": 110,
"label": "Blue Dream (Pioneer)",
},
{
"id": 30,
"label": "Candyland",
},
{
"id": 130,
"label": "Dragon OG (Avitas)",
}
]
}
我尝试执行此操作的方法是使用push,一个数组等于另一个,但仍然得到Push不是函数,或者'id'未定义并且代码停止。
这是EASY STUFF,将一个数组元素分配给另一个并不难,但是为什么这种情况如此不同?
我有在这里尝试过的示例代码:
我试过在这里使用LODASH:
//This is the call to the FIX_KEY function in appservice
_.object(
_.map(
_.keys(allStrains.data),
ctrlMain.appSvc.appFuncs.fix_key(/^name/, 'label')),
_.values(allStrains.data)
);
这是appservice中的函数:
svc.appFuncs = {
//https://stackoverflow.com/questions/32452014/change-key-name-in-javascript-object
//This replaces a STATIC key value for now, but can probably
//replace any value
fix_key: function (key, keyname) {
return key.replace(key, keyname);
}
}
我在注释中的堆栈溢出问题中修改了lodash代码。
更新1:
安德列兹(Andrjez),请查看最终结果,了解我如何进行这项工作以及在哪里遇到问题:
* Angular Dropdown Multi-select
*
* For STRAINS to select what will be in the room selected
*
*/
$scope.example8model = [];
//Get the data from LOCALSTORAGE
var getResults;
**//I GET THE RESULTS from LOCAL STORAGE HERE**
getResults = storageLocalService.getItemJSON("allstrains");
**//CHECK the strains from LOCAL STORAGE**
console.log("Strains: ", getResults.strains); //FAILS HERE!!!
//getResults.strains is UNDEFINED but getResults HOLDS the JSON
//EXACTLY how you made it in your example. I just changed
//**obj** to **getResults**.
var result = {
//NEXT LINE FAILS: getResults.strains.map is UNDEFINED!
strains: getResults.strains.map(function (item) {
return {
id: item.id,
label: item.label
};
})
};
console.log("All extracted Strains: ", result);
$scope.example8model = result;
//$scope.example8data = [
// {id: 1, label: "David"},
// {id: 2, label: "Jhon"},
// {id: 3, label: "Danny"}
//];
$scope.example8settings = {
checkBoxes: true
};
这是问题所在:LOCAL STORAGE中的数据在开头或结尾都没有双引号。 但...
这是我在DEV CONSOLE中得到的:
然后,当我单击到下一级时,会添加双引号,从而使尝试访问变得混乱:getResults.strains.map()...
最后,产生的错误...
那么,我哪里出问题了?
注意:这就是我要实现的: 多重选择
使用Array.prototype.map
:
var result = {
strains: obj.strains.map(function (item) {
return {
id: item.id,
label: item.label
};
})
};
尝试下面的代码片段以查看结果:
var obj = { "strains":[ { "id": 150, "name": "Animal Cookies (Phat Panda)", "label": "Animal Cookies (Phat Panda)", "thcpct": 14, "cbdpct": 19, "ttlpct": 33, "type": "Hybrid SD", "subtype": "Sativa Dominant", "bitactive": 1, "useradded": "jjones", "dateadded": "4/12/2017" }, { "id": 110, "name": "Blue Dream (Pioneer)", "label": "Blue Dream (Pioneer)", "thcpct": 24, "cbdpct": 0, "ttlpct": 24, "type": "Sativa", "subtype": "None", "bitactive": 1, "useradded": "jjones", "dateadded": "3/27/2017" }, { "id": 30, "name": "Candyland", "label": "Candyland", "thcpct": 25, "cbdpct": 75, "ttlpct": 100, "type": "Hybrid SD", "subtype": "Sativa Dominant", "bitactive": 1, "useradded": "jjones", "dateadded": "1/1/2017" }, { "id": 130, "name": "Dragon OG (Avitas)", "label": "Dragon OG (Avitas)", "thcpct": 26, "cbdpct": 18, "ttlpct": 44, "type": "Hybrid SD", "subtype": "Sativa Dominant", "bitactive": 1, "useradded": "jjones", "dateadded": "4/10/2017" } ] }; var result = { strains: obj.strains.map(function (item) { return { id: item.id, label: item.label }; }) }; console.log(result);
如果您想使用es6功能:
const result = { strains: obj.strains.map(({id , label}) => ({id, label})) };
obj.strains = obj.strains.map(x => ({ id: x.id, label: x.label }));
如果不仅是应变,还想对每个子数组应用相同的逻辑:
let filtered = Object.entries(obj)
.filter(([k, arr]) => Array.isArray(arr))
.reduce((acc, [k, arr]) => {
acc[k] = arr.map(x => ({ id: x.id, label: x.label }));
return acc;
}, {});
我的解决方案:
var test = 'label'
var results = [];
var response = strains.forEach( obj => {
if (obj[test]) {
results = [
...results,
{
test: obj[test]
}
];
}
});
console.log('matches', results);
//output: matches, [{test: "Animal Cookies (Phat Panda)"}, {test: "Blue Dream (Pioneer)"}, {test: "Candyland"}, {test: "Dragon OG (Avitas)"}]
for (n of strains) {
n = n.filter(function(elem,index){
return (index == "id" || index == "label")
});
}
这样的东西?
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