I wanted to filter out the data. I wanted to check if data on data1 is found on data2 and to check if it has errorMessages. Please check my code below. Is there a better way to do it?
data1
[
{
"ids": "0111",
},
{
"ids": "0222",
},
{
"ids": "0333",
}
]
data2
[
{
"id": "0111",
"errorMessages": [
{
"message": ["sample error message 1"]
}
]
},
{
"id": "0333",
"errorMessages": []
}
]
Code
const output= data1.filter(
(element) => element.ids === data2.find((data) => data).id
);
console.log("output", output);
.find((data) => data) doesn't do anything useful - each item in the array is an object, which is truthy, so that'll always return the first element in the array.
If you did want to .find a matching element in the other array - then a better approach would be to make a Set of the IDs found in the other array first (Set lookup is much quicker - O(1) - than .find, which is O(n)).
You also need to implement the logic to check if the errorMessages is empty.
const data1 = [
{
"ids": "0111",
},
{
"ids": "0222",
},
{
"ids": "0333",
}
]
const data2 = [
{
"id": "0111",
"errorMessages": [
{
"message": ["sample error message 1"]
}
]
},
{
"id": "0333",
"errorMessages": []
}
]
const ids = new Set(
data2
.filter(item => item?.errorMessages.length)
.map(item => item.id)
);
const output= data1.filter(
element => ids.has(element.ids)
);
console.log("output", output);Without Set, but use Object as the map.
const IDKeys = {};
data2.forEach(data => {
if (data.errorMessages.length){
IDKeys[data.id] = true; // means valid
}
})
const filteredArray = data1.filter(data => IDKeys[data.id]);
This would be only O(n) since accessing key on object is O(1)