I'm trying to write a function in Javascript that accepts a nested array and number as two arguments and returns a new nested array with the last couple items removed in each inside array as indicated by the number argument.
For example:
*/ removeColumns([[1, 2, 3, 4],
[1, 2, 3, 4],
[1, 2, 3, 4],
[1, 2, 3, 4]], 2);
=> [[1, 2],
[1, 2],
[1, 2],
[1, 2]]
*/
I am attaching the code have written so far. This gives me a return of [[3, 4], [3, 4]. I thought the splice function always removes array elements after the provided index but here it seems to be removing elements before the index. What am I doing wrong here?
const removeColumns = (originalGrid, numColumns) => {
for (let i = 0; i < originalGrid.length; i++) {
console.log(originalGrid[i].splice(originalGrid.length - numColumns, numColumns))
console.log(originalGrid[i])
}
return originalGrid
}
let originalGrid = [
[1, 2, 3, 4],
[1, 2, 3, 4]
];
console.log(removeColumns(originalGrid, 2))
I think that should fix your issue:
originalGrid[i].length - numColumns, numColumns)
In your example
let originalGrid = [
[1, 2, 3, 4],
[1, 2, 3, 4]
];
console.log(originalGrid.length) //2
console.log(originalGrid[0].length) //4
console.log(originalGrid[1].length) //4
So in the loop don't forget to add the index:
console.log(originalGrid[i].splice(originalGrid[i].length - numColumns, numColumns))
Write a filter function. Then, you can choose which column "section" to include.
const originalGrid = [
[1, 2, 3, 4],
[1, 2, 3, 4]
];
const filter = (data, from, to) => data.map(a => a.splice(from, to));
console.log(filter(originalGrid, 0, 2));