let vegetables = ['parsnip', 'potato']
let moreVegs = ['celery', 'beetroot']

// Merge the second array into the first one
// Equivalent to vegetables.push('celery', 'beetroot')
Array.prototype.push.apply(vegetables, moreVegs)

console.log(vegetables)  // ['parsnip', 'potato', 'celery', 'beetroot']