Remove students lowest homework score in Mongo Shell

db.students.find({}, {'_id':1, 'scores': 1}, {'scores.score': 1}).forEach(function(stud) {

    var len = stud.scores.length;
    var removeIdx = -1;
    for (var i = 0; i < len; i++) {
        if (stud.scores[i].type === 'homework') {
            removeIdx = i;
        }
    }

    stud.scores.splice(removeIdx, 1)

    db.students.update({'_id': stud['_id']}, {$set: {'scores':stud.scores}})
})