Merge two arrays using values of nested object in one of the two arrays
A primer on complex array merging
By: Ajdin Imsirovic 24 March 2019
Here’s a primer on merging two complex arrays.
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Let’s say we have two arrays.
The first array has the following structure:
let arr5 = [
{ id: "101", name: "Cars" },
{ id: "102", name: "Buses" },
{ id: "103", name: "Vans" },
{ id: "104", name: "Trucks" },
{ id: "105", name: "Boats" },
]
The second array has the following structure:
let arr6 = [
{ id: "147", name: "Toyota 2000", description: "A nice red car", vehicleGroupIds: ["101","104"] },
{ id: "148", name: "RV", description: "Mobile home", vehicleGroupIds: ["102"] },
{ id: "149", name: "Toyota 2001", description: "A nice blue car", vehicleGroupIds: ["101"] },
{ id: "150", name: "Ford", description: "Blue Ford van", vehicleGroupIds: ["103"] },
{ id: "152", name: "VW", description: "A VW truck", vehicleGroupIds: ["104"] },
{ id: "153", name: "Pearl of the Seas", description: "A fine big yacht", vehicleGroupIds: ["105"] },
]
We wanna merge arrays, so we’ll do this to begin with:
arr6.forEach(memberObj => memberObj.vehicleGroupIds.forEach(vechicleGroupId => {
arr5.forEach(arr5Obj => { if(arr5Obj.id == vechicleGroupId) { console.log(`The arr5obj id ${arr5Obj.id} is the same as vechicleGroupId ${vechicleGroupId}`) } } ) } ) )
Now let’s prepare the mergedArrays array:
let mergedArrays = [];
Now we’ll write a function to combine the two arrays. Here’s the completed code:
let mergeArrays = () => {
let arr1 = arr5;
let arr2 = arr6;
arr2.forEach(memberObj => memberObj.vehicleGroupIds.forEach(groupId => {
arr1.forEach(arr1Obj => {
if (arr1Obj.id == groupId) {
mergedArrays.push({
vehicleGroupIds: arr1Obj.id,
vehicleTypeName: arr1Obj.name,
matchingId: groupId,
vechicleId: memberObj.id,
vechicleame: memberObj.name,
vehicleDescription: memberObj.description,
})
}
})
}))
}
Finally, we can just call the function with:
mergeArrays();
Here’s how the code above works:
- To be continued …
