loop.js

loop1: for (let k = 0; k < boxID.length - 1; k++) {
        for (let l = 1; l < boxID.length - 1; l++) {
            newDiff = findDiff(boxID[k], boxID[l])
            if (newDiff.diff === 1) {
                smallestDiff = newDiff
                break loop1
            }
        }
    }