How to transpose array of objects in TypeScript? - html

Question

I am having an array of objects as below:
finalList = [
[{name: john}, {name: max}, {name: rob}],
[{id: 1}, {id: 2}, {id: 3}],
[{gender: M}, {gender: F}, {gender: M}],
]
I need the array to transpose like this:
finalList = [
{name: john, id: 1, gender: M},
{name: john, id: 1, gender: M},
{name: john, id: 1, gender: M}
]
The actual array of object is in nested array. Please help me guiding to transpose the array in TypeScript.

Answer 1

Here's a nice functional way. It assumes each array in finalList has the same length and same keys (so no error handling).
const finalList = [
[{name: "john"}, {name: "max"}, {name: "rob"}],
[{id: 1}, {id: 2}, {id: 3}],
[{gender: "M"}, {gender: "F"}, {gender: "M"}],
];
console.log(finalList);
// this is a trick to create an array of a specific size with unique objects inside it
// the fill is necessary to iterate over the holed array (https://stackoverflow.com/q/40297442/2178159)
// fill({}) won't work since it's a single object ref that will be shared
const results = new Array(finalList.length).fill(null).map(() => ({}));
finalList.forEach(group => {
group.forEach((obj, i) => {
Object.assign(results[i], obj);
})
});
console.log(results);