I have an array with data:
const data = [
{
groupName: 'groupName1',
types: [
{
name: 'name1',
displayName: 'displayName1'
},
{
name: 'name2',
displayName: 'displayName2'
},
]
},
{
groupName: 'groupName2',
types: [
{
name: 'name3',
displayName: 'displayName3'
},
{
name: 'name4',
displayName: 'displayName4'
},
]
},
]
I need to transform this array so that an extra groupName field is added to each object. The output should be an array with objects as shown below:
const resultData = [
{
groupName: 'groupName1',
name: 'name1',
displayName: 'displayName1'
},
{
groupName: 'groupName1',
name: 'name2',
displayName: 'displayName2'
},
{
groupName: 'groupName2',
name: 'name3',
displayName: 'displayName3'
},
{
groupName: 'groupName2',
name: 'name4',
displayName: 'displayName4'
},
]
I tried to do it through the map array method
const data = [{"groupName":"groupName1","types":[{"name":"name1","displayName":"displayName1"},{"name":"name2","displayName":"displayName2"}]},{"groupName":"groupName2","types":[{"name":"name3","displayName":"displayName3"},{"name":"name4","displayName":"displayName4"}]}]
const resultData = data.map((item) => {
item.types.map((item1) => {
return {
...item1,
groupName: item.groupName
}
})
return item
})
console.log(resultData)But this does not return the array that I need. Please tell me how I can transform this array so that each object has the correct structure? Thank you in advance!
Replace the outer Array.map() call with Array.flatMap() to create a flat array, and return the result of the internal map call, and not the original item.
const data = [{"groupName":"groupName1","types":[{"name":"name1","displayName":"displayName1"},{"name":"name2","displayName":"displayName2"}]},{"groupName":"groupName2","types":[{"name":"name3","displayName":"displayName3"},{"name":"name4","displayName":"displayName4"}]}]
const resultData = data.flatMap(({ types, groupName }) =>
types.map(item => ({
...item,
groupName
}))
)
console.log(resultData)I would use reduce.
data.reduce((carry, {types, groupName}) => carry.concat(types.map(d => ({...d, groupName}))), []);