[javascript] 등차수열, 등비수열, pop()

arr.pop();

var myFish = ["angel", "clown", "mandarin", "sturgeon"];

var popped = myFish.pop();

console.log(myFish); // ['angel', 'clown', 'mandarin' ]

console.log(popped); // 'sturgeon'

function solution1(c) {
  if (c[1] - c[0] == c[2] - c[1]) {
    return c[c.length - 1] + c[1] - c[0];
  } else {
    return (c[c.length - 1] * c[1]) / c[0];
  }
}
function solution2(c) {
  if (c[1] - c[0] == c[2] - c[1]) {
    return c.pop() + c[1] - c[0];
  } else {
    return (c.pop() * c[1]) / c[0];
  }
}

let c = [
  [1, 2, 3, 4],
  [2, 4, 8],
];

for (let i = 0; i < c.length; i++) {
  console.log('solution1', solution1(c[i]));
  console.log('solution2', solution2(c[i]));
}

결과