I have an input like this:
var input = [
{
"inner_array": [
{
"inner_data": "inner_data1"
},
{
"inner_data": "inner_data2"
}
],
"outer_data": "outer_data",
}
];
And I'd like to process it so it becomes this.
var output = [
{
"inner_data": "inner_data1",
"outer_data": "outer_data",
},
{
"inner_data": "inner_data2",
"outer_data": "outer_data",
}
];
In words: I'd like to flatten an inner array, while still keeping the outer array's properties. Does this have an easy solution (with built in lambda array functions), or should I write a function myself which handles this?
You could use .flatMap() on your input array to loop over each object, along with an inner .map() to map each inner_array to a new object. The new object can be a combination of the outer_data value along with the inner_data value. The .flatMap() method will then merge all returned objects from the inner .map() calls for each object within input into one resulting array:
const input = [{ "inner_array": [{ "inner_data": "inner_data1" }, { "inner_data": "inner_data2" } ], "outer_data": "outer_data", }];
const res = input.flatMap(obj => obj.inner_array.map(inner => ({
...inner,
outer_data: obj.outer_data
})));
console.log(res);