shallowEqual.js

function shallowEqual(objA, objB) {
  if (objA === objB) {
    return true;
  }
  if (
    !(typeof objA === 'object' && objA != null) ||
    !(typeof objB === 'object' && objB != null)
  ) {
    return false;
  }
  const keysA = Object.keys(objA);
  const keysB = Object.keys(objB);
  if (keysA.length !== keysB.length) {
    return false;
  }
  for (let i = 0; i < keysA.length; i++) {
    if (objB.hasOwnProperty(keysA[i])) {
      if (objA[keysA[i]] !== objB[keysA[i]]) {
        console.log('不相等的Key', keysA[i]);
        return false;
      }
    } else {
      return false;
    }
  }
  return true;
}