1const array1 = ['a', 'b', 'c'];
2const array2 = ['d', 'e', 'f'];
3const array3 = [...array1, ...array2];
4
5console.log(array3);
6// expected output: Array ["a", "b", "c", "d", "e", "f"]
1const _questions = _.map(this.sections, section => section.questions);
2const questions = Array.prototype.concat.apply([], _questions);