问题
I got following data structure, which is an array of accounts objects, where some accounts are being parents to its children accounts, which in turn can be parents to other accounts etc.:
[{
"id": "acc.1260446672222.11",
"type": "EXPENSES_FOLDER",
"name": "Expense Group",
"balance": 3418.11,
"children": [{
"id": "acc.1260446672238.27",
"type": "EXPENSE",
"name": "Advertising, Promotion and Entertainment Account",
"balance": 0,
"children": []
}, {
"id": "acc.9a2492ba-0d82-4f4a-a1b4-14868f1e1a39",
"type": "EXPENSES_FOLDER",
"name": "Premises Costs",
"balance": 0,
"children": [{
"id": "acc.287ba5b6-5536-428b-950f-d71d2af73ccc",
"type": "EXPENSE",
"name": "Use of Home - Gas",
"balance": 0,
"children": [
]
}, {
"id": "acc.7091ee15-3f02-4bd1-94e5-5918cf986969",
"type": "EXPENSE",
"name": "Hire of Venue, Studios, Teaching Rooms",
"balance": 0,
"children": [
]
}]
}, {
"id": "acc.827ec446-edeb-4f2b-8032-d306292d2d83",
"type": "EXPENSES_FOLDER",
"name": "Administrative Expenses",
"balance": 558.61,
"children": [{
"id": "acc.0ed5fc81-7734-4452-86a9-db22a6b0f8e8",
"type": "EXPENSE",
"name": "Bank Charges",
"balance": 15,
"children": [
]
}, {
"id": "acc.e2cdb2c0-8565-4991-a35a-d4596b0ddf45",
"type": "EXPENSE",
"name": "Software & Computer Peripherals",
"balance": 417.13,
"children": [
]
}, {
"id": "acc.96d5d00e-43f4-4d3a-b97b-fdf258c65514",
"type": "EXPENSE",
"name": "Printing, photocopying etc",
"balance": 55.93,
"children": [
]
}, {
"id": "acc.494dd64a-4fb3-42b8-be3e-8f3b59a2ef59",
"type": "EXPENSE",
"name": "Artists Administration Service",
"balance": 0,
"children": [
]
}, {
"id": "acc.1260446672238.35",
"type": "EXPENSE",
"name": "Stationery",
"balance": 0,
"children": [
]
}, {
"id": "acc.96d89d0d-5465-488b-b37f-d41ca114c5e6",
"type": "EXPENSE",
"name": "Mobile Telephone",
"balance": 41.19,
"children": [
]
}, {
"id": "acc.1260446672238.33",
"type": "EXPENSE",
"name": "Home Telephone",
"balance": 0,
"children": [
]
}, {
"id": "acc.1260446672238.38",
"type": "EXPENSE",
"name": "Postage/delivery",
"balance": 29.36,
"children": [
]
}]
}, {
"id": "acc.b9c9bbc7-43df-472e-9ac8-c7c76f08f49a",
"type": "EXPENSES_FOLDER",
"name": "Instruments, Equipment Maintenance etc",
"balance": 1002.48,
"children": [{
"id": "acc.1260446672238.32",
"type": "OTHER_EXPENSES",
"name": "Instrument Insurance",
"balance": 157.48,
"children": [
]
}, {
"id": "acc.2a1cca15-2868-4770-a3e7-d43a6268c6a1",
"type": "EXPENSE",
"name": "Instrument Repairs & Maintenance",
"balance": 845,
"children": [
]
}, {
"id": "acc.a908aee0-84fb-450a-916b-4cec25265aef",
"type": "EXPENSE",
"name": "Accessories & Replacement Parts",
"balance": 0,
"children": [
]
}]
}, {
"id": "acc.a42cdd86-0d9e-4f3f-af0d-7c4525374731",
"type": "EXPENSES_FOLDER",
"name": "Motor Vehicle",
"balance": 0,
"children": [{
"id": "acc.cb325e7e-0ce4-4c78-9cb4-20659df733a6",
"type": "EXPENSE",
"name": "Fuel and Oil",
"balance": 0,
"children": [
]
}]
}, {
"id": "acc.4bdd9e26-ce64-4e7f-b46a-82ec9de06ded",
"type": "EXPENSES_FOLDER",
"name": "Other Travel",
"balance": 132.1,
"children": [{
"id": "acc.77dd2142-f2de-4a2c-9247-061d0661bc0a",
"type": "EXPENSE",
"name": "Taxis",
"balance": 24.5,
"children": [
]
}, {
"id": "acc.2b54abdd-7ef5-43cd-bdb9-c8c981b59ff2",
"type": "EXPENSE",
"name": "Public Transport",
"balance": 107.6,
"children": [
]
}]
}, {
"id": "acc.e4695b70-31fa-4e23-afd0-97335dcd5b9e",
"type": "EXPENSE",
"name": "Subsitence",
"balance": 0,
"children": [
]
}, {
"id": "acc.02d222bf-4dff-4308-afe9-69b93f412ada",
"type": "EXPENSE",
"name": "Hotel and Accomodation",
"balance": 0,
"children": [
]
}, {
"id": "acc.d61cd5b4-2c80-4ab8-93d0-9d5726bd253b",
"type": "EXPENSES_FOLDER",
"name": "Fees and Commission Paid",
"balance": 0,
"children": [{
"id": "acc.1262189019758.7",
"type": "EXPENSE",
"name": "Pupils exam entry fees",
"balance": 0,
"children": [
]
}, {
"id": "acc.a7d7efd3-d0da-4704-babb-079b6077f3fe",
"type": "EXPENSE",
"name": "Audition, competition entry fees",
"balance": 0,
"children": [
]
}, {
"id": "acc.3b91ee4e-40a8-46d8-aa05-3afa5974b3ef",
"type": "EXPENSE",
"name": "Deputies, Other Musicians",
"balance": 0,
"children": [
]
}]
}, {
"id": "acc.250d6872-6023-4599-a0b6-b7159eebbfa1",
"type": "EXPENSES_FOLDER",
"name": "Other Professional Expenses",
"balance": 1739.42,
"children": [{
"id": "acc.b7315228-f85a-4ffb-9199-d1128a409e5f",
"type": "EXPENSE",
"name": "Promotion & Publicity",
"balance": 138.6,
"children": [
]
}, {
"id": "acc.69ca2005-d7a0-448b-b70c-dafb128a48ae",
"type": "EXPENSE",
"name": "Other Expenses",
"balance": 364.5,
"children": [
]
}, {
"id": "acc.dcd999d2-4e18-41be-b9cc-218d4034b88e",
"type": "EXPENSE",
"name": "Office Equipment, Furniture",
"balance": 0,
"children": [
]
}, {
"id": "acc.e0460706-d5c9-4c40-9d1e-0d2058864b92",
"type": "EXPENSE",
"name": "CDs, Dowloads etc",
"balance": 67.57,
"children": [
]
}, {
"id": "acc.1866df79-9e44-459a-a978-727904987469",
"type": "EXPENSE",
"name": "Professional Books, Magazines",
"balance": 104.01,
"children": [
]
}, {
"id": "acc.24c1651d-e7ae-48bc-a32d-311427e0fcea",
"type": "EXPENSE",
"name": "Professional Associations",
"balance": 272.17,
"children": [
]
}, {
"id": "acc.289ab0ac-b9d3-435e-ac82-9da9702b7d4b",
"type": "EXPENSE",
"name": "Tuition",
"balance": 470,
"children": [
]
}, {
"id": "acc.f24cf99b-6291-4b9f-821e-425f4909d4e1",
"type": "EXPENSE",
"name": "Scores, Manuscript Paper etc",
"balance": 215.32,
"children": [
]
}, {
"id": "acc.1af95953-56f0-455e-9d0a-7c4e0477cf0d",
"type": "EXPENSE",
"name": "Performance Clothing",
"balance": 0,
"children": [
]
}, {
"id": "acc.c0585577-535a-4ae2-a02b-e5b249f67c67",
"type": "EXPENSE",
"name": "Concerts, Shows etc",
"balance": 107.25,
"children": [
]
}]
}, {
"id": "acc.1260446672222.24",
"type": "ADMIN",
"name": "Administrative Expenses",
"balance": 0,
"children": [
]
}, {
"id": "acc.1260446672238.26",
"type": "TRAVEL",
"name": "Travel and Subsistence Account",
"balance": -14.5,
"children": [
]
}, {
"id": "acc.1260446672238.28",
"type": "LEGAL",
"name": "Legal and Professional Costs Account",
"balance": 0,
"children": [
]
}, {
"id": "acc.1260446672238.36",
"type": "OTHER_EXPENSES",
"name": "Rent/Rates",
"balance": 0,
"children": [
]
}, {
"id": "acc.1262191376548.37",
"type": "EXPENSE",
"name": "Research",
"balance": 0,
"children": [
]
}, {
"id": "acc.1262191388329.38",
"type": "EXPENSE",
"name": "Professional Development",
"balance": 0,
"children": [
]
}, {
"id": "acc.1262192291558.52",
"type": "EXPENSE",
"name": "Professional Presentation",
"balance": 0,
"children": [
]
}, {
"id": "acc.1262193596634.72",
"type": "EXPENSE",
"name": "Subscriptions",
"balance": 0,
"children": [
]
}, {
"id": "acc.1262265941130.16",
"type": "EXPENSE",
"name": "Piano accompaniment",
"balance": 0,
"children": [
]
}, {
"id": "acc.1267370824329.1",
"type": "EXPENSE",
"name": "Cost of Sales",
"balance": 0,
"children": [
]
}]
}]
What I need is to flatten this array to have a flat list of accounts. What's the way to proceed with that in Vanilla JavaScript. (I also got access to lodash methods in my project).
回答1:
Just iterate over and if a children is found get the array from the children concatinated.
function flat(array) {
var result = [];
array.forEach(function (a) {
result.push(a);
if (Array.isArray(a.children)) {
result = result.concat(flat(a.children));
}
});
return result;
}
var data = [{ id: "acc.1260446672222.11", type: "EXPENSES_FOLDER", name: "Expense Group", balance: 3418.11, children: [{ id: "acc.1260446672238.27", type: "EXPENSE", name: "Advertising, Promotion and Entertainment Account", balance: 0, children: [] }, { id: "acc.9a2492ba-0d82-4f4a-a1b4-14868f1e1a39", type: "EXPENSES_FOLDER", name: "Premises Costs", balance: 0, children: [{ id: "acc.287ba5b6-5536-428b-950f-d71d2af73ccc", type: "EXPENSE", name: "Use of Home - Gas", balance: 0, children: [] }, { id: "acc.7091ee15-3f02-4bd1-94e5-5918cf986969", type: "EXPENSE", name: "Hire of Venue, Studios, Teaching Rooms", balance: 0, children: [] }] }, { id: "acc.827ec446-edeb-4f2b-8032-d306292d2d83", type: "EXPENSES_FOLDER", name: "Administrative Expenses", balance: 558.61, children: [{ id: "acc.0ed5fc81-7734-4452-86a9-db22a6b0f8e8", type: "EXPENSE", name: "Bank Charges", balance: 15, children: [] }, { id: "acc.e2cdb2c0-8565-4991-a35a-d4596b0ddf45", type: "EXPENSE", name: "Software & Computer Peripherals", balance: 417.13, children: [] }, { id: "acc.96d5d00e-43f4-4d3a-b97b-fdf258c65514", type: "EXPENSE", name: "Printing, photocopying etc", balance: 55.93, children: [] }, { id: "acc.494dd64a-4fb3-42b8-be3e-8f3b59a2ef59", type: "EXPENSE", name: "Artists Administration Service", balance: 0, children: [] }, { id: "acc.1260446672238.35", type: "EXPENSE", name: "Stationery", balance: 0, children: [] }, { id: "acc.96d89d0d-5465-488b-b37f-d41ca114c5e6", type: "EXPENSE", name: "Mobile Telephone", balance: 41.19, children: [] }, { id: "acc.1260446672238.33", type: "EXPENSE", name: "Home Telephone", balance: 0, children: [] }, { id: "acc.1260446672238.38", type: "EXPENSE", name: "Postage/delivery", balance: 29.36, children: [] }] }, { id: "acc.b9c9bbc7-43df-472e-9ac8-c7c76f08f49a", type: "EXPENSES_FOLDER", name: "Instruments, Equipment Maintenance etc", balance: 1002.48, children: [{ id: "acc.1260446672238.32", type: "OTHER_EXPENSES", name: "Instrument Insurance", balance: 157.48, children: [] }, { id: "acc.2a1cca15-2868-4770-a3e7-d43a6268c6a1", type: "EXPENSE", name: "Instrument Repairs & Maintenance", balance: 845, children: [] }, { id: "acc.a908aee0-84fb-450a-916b-4cec25265aef", type: "EXPENSE", name: "Accessories & Replacement Parts", balance: 0, children: [] }] }, { id: "acc.a42cdd86-0d9e-4f3f-af0d-7c4525374731", type: "EXPENSES_FOLDER", name: "Motor Vehicle", balance: 0, children: [{ id: "acc.cb325e7e-0ce4-4c78-9cb4-20659df733a6", type: "EXPENSE", name: "Fuel and Oil", balance: 0, children: [] }] }, { id: "acc.4bdd9e26-ce64-4e7f-b46a-82ec9de06ded", type: "EXPENSES_FOLDER", name: "Other Travel", balance: 132.1, children: [{ id: "acc.77dd2142-f2de-4a2c-9247-061d0661bc0a", type: "EXPENSE", name: "Taxis", balance: 24.5, children: [] }, { id: "acc.2b54abdd-7ef5-43cd-bdb9-c8c981b59ff2", type: "EXPENSE", name: "Public Transport", balance: 107.6, children: [] }] }, { id: "acc.e4695b70-31fa-4e23-afd0-97335dcd5b9e", type: "EXPENSE", name: "Subsitence", balance: 0, children: [] }, { id: "acc.02d222bf-4dff-4308-afe9-69b93f412ada", type: "EXPENSE", name: "Hotel and Accomodation", balance: 0, children: [] }, { id: "acc.d61cd5b4-2c80-4ab8-93d0-9d5726bd253b", type: "EXPENSES_FOLDER", name: "Fees and Commission Paid", balance: 0, children: [{ id: "acc.1262189019758.7", type: "EXPENSE", name: "Pupils exam entry fees", balance: 0, children: [] }, { id: "acc.a7d7efd3-d0da-4704-babb-079b6077f3fe", type: "EXPENSE", name: "Audition, competition entry fees", balance: 0, children: [] }, { id: "acc.3b91ee4e-40a8-46d8-aa05-3afa5974b3ef", type: "EXPENSE", name: "Deputies, Other Musicians", balance: 0, children: [] }] }, { id: "acc.250d6872-6023-4599-a0b6-b7159eebbfa1", type: "EXPENSES_FOLDER", name: "Other Professional Expenses", balance: 1739.42, children: [{ id: "acc.b7315228-f85a-4ffb-9199-d1128a409e5f", type: "EXPENSE", name: "Promotion & Publicity", balance: 138.6, children: [] }, { id: "acc.69ca2005-d7a0-448b-b70c-dafb128a48ae", type: "EXPENSE", name: "Other Expenses", balance: 364.5, children: [] }, { id: "acc.dcd999d2-4e18-41be-b9cc-218d4034b88e", type: "EXPENSE", name: "Office Equipment, Furniture", balance: 0, children: [] }, { id: "acc.e0460706-d5c9-4c40-9d1e-0d2058864b92", type: "EXPENSE", name: "CDs, Dowloads etc", balance: 67.57, children: [] }, { id: "acc.1866df79-9e44-459a-a978-727904987469", type: "EXPENSE", name: "Professional Books, Magazines", balance: 104.01, children: [] }, { id: "acc.24c1651d-e7ae-48bc-a32d-311427e0fcea", type: "EXPENSE", name: "Professional Associations", balance: 272.17, children: [] }, { id: "acc.289ab0ac-b9d3-435e-ac82-9da9702b7d4b", type: "EXPENSE", name: "Tuition", balance: 470, children: [] }, { id: "acc.f24cf99b-6291-4b9f-821e-425f4909d4e1", type: "EXPENSE", name: "Scores, Manuscript Paper etc", balance: 215.32, children: [] }, { id: "acc.1af95953-56f0-455e-9d0a-7c4e0477cf0d", type: "EXPENSE", name: "Performance Clothing", balance: 0, children: [] }, { id: "acc.c0585577-535a-4ae2-a02b-e5b249f67c67", type: "EXPENSE", name: "Concerts, Shows etc", balance: 107.25, children: [] }] }, { id: "acc.1260446672222.24", type: "ADMIN", name: "Administrative Expenses", balance: 0, children: [] }, { id: "acc.1260446672238.26", type: "TRAVEL", name: "Travel and Subsistence Account", balance: -14.5, children: [] }, { id: "acc.1260446672238.28", type: "LEGAL", name: "Legal and Professional Costs Account", balance: 0, children: [] }, { id: "acc.1260446672238.36", type: "OTHER_EXPENSES", name: "Rent/Rates", balance: 0, children: [] }, { id: "acc.1262191376548.37", type: "EXPENSE", name: "Research", balance: 0, children: [] }, { id: "acc.1262191388329.38", type: "EXPENSE", name: "Professional Development", balance: 0, children: [] }, { id: "acc.1262192291558.52", type: "EXPENSE", name: "Professional Presentation", balance: 0, children: [] }, { id: "acc.1262193596634.72", type: "EXPENSE", name: "Subscriptions", balance: 0, children: [] }, { id: "acc.1262265941130.16", type: "EXPENSE", name: "Piano accompaniment", balance: 0, children: [] }, { id: "acc.1267370824329.1", type: "EXPENSE", name: "Cost of Sales", balance: 0, children: [] }] }],
result = flat(data);
document.write('<pre>' + JSON.stringify(result, 0, 4) + '</pre>');回答2:
try to understand this version, with it's benefits and implications
function flatten(into, node){
if(node == null) return into;
if(Array.isArray(node)) return node.reduce(flatten, into);
into.push(node);
return flatten(into, node.children);
}
var out = flatten([], yourArray);
the argument order might be confusing at first, unless you are used to reduced, or the concept of options first, data last, wich is very handy when it comes to FP and currying or partial application.
回答3:
You could make a recursive function that looks through each account, and if it has children calls itself on the children, the function should return a flattened array of accounts.
This example is a bit more complicated than it has to be because I am assuming that order matters and that the parent should be before the children.
function flattenAccounts(accounts){
var a = [];
for(var i=0;i<accounts.length;i++){
var o = accounts[i];
if(o.children){
var c = flattenAccounts(o.children);
if(c){
a = a.concat(c);
}
}
a.push(o)
}
return a;
}This is a simpler example but the children would end up before the parent.
function flattenAccounts(accounts){
var a = [];
for(var i=0;i<accounts.length;i++){
if(accounts[i].children){
a = a.concat(flattenAccounts(accounts[i].children) )
}
a.push(accounts[i])
}
return a;
}来源：https://stackoverflow.com/questions/35272533/flattening-deeply-nested-array-of-objects