1.7 KiB
1.7 KiB
title | id | challengeType |
---|---|---|
Vector cross product | 594810f028c0303b75339ad2 | 5 |
Description
Task:
Write a function that takes two vectors (arrays) as input and computes their cross product.
Your function should return null
on
invalid inputs (ie vectors of different lengths).
Instructions
Tests
tests:
- text: dotProduct must be a function
testString: assert.equal(typeof crossProduct, 'function', 'dotProduct must be a function');
- text: dotProduct() must return null
testString: assert.equal(crossProduct(), null, 'dotProduct() must return null');
- text: crossProduct([1, 2, 3], [4, 5, 6]) must return [-3, 6, -3].
testString: assert.deepEqual(res12, exp12, 'crossProduct([1, 2, 3], [4, 5, 6]) must return [-3, 6, -3].');
Challenge Seed
function crossProduct() {
// Good luck!
}
After Test
const tv1 = [1, 2, 3];
const tv2 = [4, 5, 6];
const res12 = crossProduct(tv1, tv2);
const exp12 = [-3, 6, -3];
Solution
function crossProduct(a, b) {
if (!a || !b) {
return null;
}
// Check lengths
if (a.length !== 3 || b.length !== 3) {
return null;
}
return [
(a[1] * b[2]) - (a[2] * b[1]),
(a[2] * b[0]) - (a[0] * b[2]),
(a[0] * b[1]) - (a[1] * b[0])
];
}