Lets assume I have the following array:

const arr = [ '0', 'parentNode', 'children', '0', 'values' ]

And my goal is to cut the array until when a certain string matches (everything after that string).

So if I choose children as the string, the result would be:

const arr = [ '0', 'parentNode', 'children']

My current implementation works, I am creating a big function and iterating over the array, push each element to a new array when a condition holds....

But I would like to have a more elegant solution, maybe a oneliner.

In Python, this is possible, how would this look like in JavaScript?

CodePudding user response：

There are lots of ways.

indexof (findIndex if you need to use a callback because the comparison is more complicated) and slice:

const index = arr.indexOf(target);
const result = index < 0 ? [] : arr.slice(index);

A simple loop:

const result = [];
let found = false;
for (const element of arr) {
    found = found || element === target;
    if (found) {
        result.push(element);
    }
}

filter:

let found = false;
const result = arr.filter(element => {
    found = found || element === target;
    return found;
});

CodePudding user response：

This is the one-liner solution:

arr.slice(0, arr.indexOf('children') 1)

It performs well, because uses native code (V8, SpiderMonkey, etc...). But does not handle errors. If no 'children' is found, you'll receive empty array.