There is sourceArray and some additionalArray. Need to add items from additionalArray to the end of sourceArray. And in result sourceArray contains all items (no create new array). The problem is items count of additionalArray may be thousands.
// example
push([], [1, 2, 3], [10, 20, 30]) // [1, 2, 3, 10, 20, 30]
push(['a', 'b'], 'x', ['z', '0']) // ['a', 'b', 'x', 'z', '0']
// my solution
function push(sourceArray, ...additionalArray) {
additionalArray.forEach((array) => {
array = Array.isArray(array) ? array : [array];
if (array.length < 1000) {
sourceArray.push.apply(sourceArray, array);
} else {
array.forEach((item) => sourceArray.push(item));
}
});
return sourceArray;
}
My question is there more elegant solution for this task?
You might find using .flat() can help you here. If you use that on additionalArray, you can then spread ... those elements into a call to .push() as arguments:
const push = (source, ...rest) => {
source.push(...rest.flat());
return source;
}
console.log(push([], [1, 2, 3], [10, 20, 30])) // [1, 2, 3, 10, 20, 30]
console.log(push(['a', 'b'], 'x', ['z', '0'])) // ['a', 'b', 'x', 'z', '0']This does have a limitation though in that .push() can only accept a certain amount of arguments. You might hit the max argument limit and this can throw considering that your additionalArray can be large. Using a for..of loop would help with that:
const push = (source, ...rest) => {
for(const item of rest.flat())
source.push(item)
return source;
}
console.log(push([], [1, 2, 3], [10, 20, 30])) // [1, 2, 3, 10, 20, 30]
console.log(push(['a', 'b'], 'x', ['z', '0'])) // ['a', 'b', 'x', 'z', '0']As of MDN, you can use the array spread syntax:
let vegetables = ['parsnip', 'potato']
let moreVegs = ['celery', 'beetroot']
// Merge the second array into the first one
vegetables.push(...moreVegs);
console.log(vegetables) // ['parsnip', 'potato', 'celery', 'beetroot']