Run results for: Object.entries vs ...

Test name	Executions per second
✓ ObjToArr5	246 Ops/sec
ObjToArr	212 Ops/sec
ObjToArr4	193 Ops/sec
ObjToArr3	189 Ops/sec
ObjToArr2	183 Ops/sec
Object.entries	155 Ops/sec

Script Preparation code:

var obj = {};
for (let i = 0; i < 100000; i++) {
  obj[i] = i;
}

var ObjToArr = (obj)=> {
  if (obj == null) { // null 또는 undefined 검사
    throw new TypeError('Cannot convert undefined or null to object');
  }

  const ownProps = Object.keys(obj); // 객체의 자체 열거 가능한 속성 키를 가져옵니다.
  const length = ownProps.length;
  const result = new Array(length);

  for (let i = 0; i < length; i++) {
    result[i] = [ownProps[i], obj[ownProps[i]]]; // [key, value] 쌍을 생성합니다.
  }

  return result;
}

var ObjToArr2 = (obj)=> {
  if (obj == null) { // null 또는 undefined 검사
    throw new TypeError('Cannot convert undefined or null to object');
  }

  const result = [];
  Object.keys(obj).forEach((key) => result.push([key, obj[key]]));
  
  return result;
}

var ObjToArr3 = (obj)=> {
  if (obj == null) { // null 또는 undefined 검사
    throw new TypeError('Cannot convert undefined or null to object');
  }

  const result = [];

  Object.keys(obj).forEach((key) => result.push([key, obj[key]]));
  
  return result;
}

var ObjToArr4 = (obj)=> {
  if (obj == null) { // null 또는 undefined 검사
    throw new TypeError('Cannot convert undefined or null to object');
  }

  const result = []
  for(const key of Object.keys(obj)) result.push([key, obj[key]]);
  
  return result;
}


var ObjToArr5 = (obj)=> {
  if (obj == null) return;

  const result = []
  for(const key in obj) result.push([key, obj[key]]);
  
  return result;
}