4 回答

TA貢獻1869條經驗 獲得超4個贊
let final = [];
for (var i = 0, len = positions.length; i < len; i++) {
? let a = [];
? for (var j = 0, jlen = positions[i]["geometry"]["geometries"].length; j < jlen; j++) {
? ??
? ? for (var k = 0, klen = positions[i]["geometry"]["geometries"][j]["coordinates"].length; k < klen; k++) {
? ??
? ? ? for (l = 0, llen = positions[i]["geometry"]["geometries"][j]["coordinates"][k].length; l < llen; l++) {
? ? ? ? a = a.concat(positions[i]["geometry"]["geometries"][j]["coordinates"][k][l]);
? ? ? }
? ? }
? }
? final.push(a);
}
console.log(final);

TA貢獻1796條經驗 獲得超4個贊
您可以使用 forEach 來實現,以獲得更好的性能。
let positions = [
{
type: "Feature",
geometry: {
type: "GeometryCollection",
geometries: [
{
type: "Polygon",
coordinates: [
[
[-4.66478, 58.42441, 5127.4],
[-4.65982, 58.42082, 5074.7],
],
],
},
],
},
id: "kml_1",
},
{
type: "Feature",
geometry: {
type: "GeometryCollection",
geometries: [
{
type: "Polygon",
coordinates: [
[
[-3.94815, 57.71632, 5000],
[-3.94812, 57.71576, 4374.1],
],
],
},
{
type: "Polygon",
coordinates: [
[
[-3.94216, 57.71541, 4283],
[-3.93717, 57.71583, 5001],
],
],
},
],
},
id: "kml_2",
},
{
type: "Feature",
geometry: {
type: "GeometryCollection",
geometries: [
{
type: "Polygon",
coordinates: [
[
[-3.93224, 57.71476, 4048],
[-3.93261, 57.71456, 3800.4],
],
],
},
],
},
id: "kml_3",
},
];
let newPolygons = []
const flatPositions = (arr)=>{
arr.forEach((pos)=>{
let p = []
pos?.geometry?.geometries.forEach((geometry)=>{
geometry?.coordinates.forEach(coord=>{
coord.forEach(coo=>{
p = p.concat(coo)
})
})
})
newPolygons.push(p)
})
}
flatPositions(positions)
console.log(newPolygons)

TA貢獻1784條經驗 獲得超7個贊
只需使用Array.prototype.reduce()
和Array.prototype.flat()
以及解構賦值
const arrGeo = positions.reduce((a,{geometry})=>
? {
? let item = []
? for (let geo of geometry.geometries)
? ? {
? ? let p = geo.coordinates.reduce((t,c)=>
? ? ? {
? ? ? t.push(...c.flat())
? ? ? return t
? ? ? },[])
? ? ? item.push(...p)
? ? }
? a.push(item)
? return a
? },[])
完整代碼:
const positions =?
? ? ? [ { type: 'Feature'
? ? ? ? , geometry:?
? ? ? ? ? { type: 'GeometryCollection'
? ? ? ? ? , geometries:?
? ? ? ? ? ? [ { type: 'Polygon'
? ? ? ? ? ? ? , coordinates:?
? ? ? ? ? ? ? ? [ [ [ -4.66478, 58.42441, 5127.4]?
? ? ? ? ? ? ? ? ? , [ -4.65982, 58.42082, 5074.7]?
? ? ? ? ? ] ] } ] }?
? ? ? ? , id: 'kml_1'
? ? ? ? }?
? ? ? , { type: 'Feature'
? ? ? ? , geometry:?
? ? ? ? ? { type: 'GeometryCollection'
? ? ? ? ? , geometries:?
? ? ? ? ? ? [ { type: 'Polygon'
? ? ? ? ? ? ? , coordinates:?
? ? ? ? ? ? ? ? [ [ [ -3.94815, 57.71632, 5000? ?]?
? ? ? ? ? ? ? ? ? , [ -3.94812, 57.71576, 4374.1 ]?
? ? ? ? ? ? ? ] ] }?
? ? ? ? ? ? , { type: 'Polygon'
? ? ? ? ? ? ? , coordinates:?
? ? ? ? ? ? ? ? [ [ [ -3.94216, 57.71541, 4283]?
? ? ? ? ? ? ? ? ? , [ -3.93717, 57.71583, 5001]?
? ? ? ? ? ] ] } ] }?
? ? ? ? , id: 'kml_2'
? ? ? ? }?
? ? ? , { type: 'Feature'
? ? ? ? , geometry:?
? ? ? ? ? { type: 'GeometryCollection'
? ? ? ? ? , geometries:?
? ? ? ? ? ? [ { type: 'Polygon'
? ? ? ? ? ? ? , coordinates:?
? ? ? ? ? ? ? ? [ [ [ -3.93224, 57.71476, 4048]?
? ? ? ? ? ? ? ? ? , [ -3.93261, 57.71456, 3800.4]?
? ? ? ? ? ] ] } ] }?
? ? ? ? , id: 'kml_3'
? ? ? } ]?
const arrGeo = positions.reduce((a,{geometry})=>
? {
? let item = []
? for( let geo of geometry.geometries )
? ? {
? ? let p = geo.coordinates.reduce((t,c)=>
? ? ? {
? ? ? t.push(...c.flat())
? ? ? return t
? ? ? },[])
? ? ? item.push(...p)
? ? }
? a.push(item)
? return a
? },[])
arrGeo.forEach(el=> console.log(JSON.stringify(el)))
.as-console-wrapper { max-height: 100% !important; top: 0; }

TA貢獻1810條經驗 獲得超4個贊
我不確定,但如果我理解正確,這應該是理想的結果。我希望我有所幫助。
positions =
[
{
"type": "Feature",
"geometry": {
"type": "GeometryCollection",
"geometries": [
{
"type": "Polygon",
"coordinates": [
[
[-4.66478, 58.42441, 5127.4],
[-4.65982, 58.42082, 5074.7],
]
]
},
]
},
"id": "kml_1"
},
{
"type": "Feature",
"geometry": {
"type": "GeometryCollection",
"geometries": [
{
"type": "Polygon",
"coordinates": [
[
[-3.94815, 57.71632, 5000],
[-3.94812, 57.71576, 4374.1],
]
]
},
{
"type": "Polygon",
"coordinates": [
[
[-3.94216, 57.71541, 4283],
[-3.93717, 57.71583, 5001],
]
]
},
]
},
"id": "kml_2"
},
{
"type": "Feature",
"geometry": {
"type": "GeometryCollection",
"geometries": [
{
"type": "Polygon",
"coordinates": [
[
[-3.93224, 57.71476, 4048],
[-3.93261, 57.71456, 3800.4],
]
]
},
]
},
"id": "kml_3"
},
];
var arrGeo = [];
var res = [];
for (var i = 0; i < positions.length; i++) {
var x = positions[i].geometry.geometries;
var f = [];
for (var ii = 0; ii < x.length; ii++) {
var z = x[ii].coordinates[0];
var t = z.flat();
f.push(t)
}
res.push(f);
for (let ii = 0; ii < res.length; ii++) {
res[ii].flat();
}
}
for (var i = 0; i < res.length; i++) {
arrGeo.push(res[i].flat());
}
console.log(arrGeo);
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