А
Size: a a a
А
IS
const isNotExist = !arr.some(/* ... */);
IS
IS
IS
AP
if (!isNotExist)
IS
БО
IS
const not = a => !a;
хдIS
if(not(exist)) {}
А
А
IS
AP
А
А
IS
const isNotExist = !isExist;
А
IS
posts.some(({ id }) => id === newPost.id) || posts.push({ ...newPost, id: newPost.id + 1 });
IS