some() function is not working with && operator

Question

I´m triying to use the some() function with && operator, but always return false, even if both conditions are inside in the array. For example:

  if (acciones.some(a => a.accionID == 7 && a.accionID == 8)) {
    return true;
  } else {
    return false;
  }

Answer 1

You're checking one specific accionID on each call to the some callback. That one accionID cannot be both == 7 and == 8 at the same time. Any given accionID will be 7 or 8.

If you want to see if all of the acciones have accionID of 7 or 8, use every with ||:

if (acciones.every(a => a.accionID == 7 || a.accionID == 8)) {
// ----------^--------------------------^

If you want to see if any of the acciones has an accionID of 7 or 8, use some with ||:

if (acciones.some(a => a.accionID == 7 || a.accionID == 8)) {
// ----------^-------------------------^

If acciones has at least one entry in it where accionID is (say) 6, the every check will be false, and the some check will be true.

---

Since some and every already return a boolean, there's no need for:

if (acciones.every(a => a.accionID == 7 || a.accionID == 8)) {
    return true;
} else {
    return false;
}

Just use

return acciones.every(a => a.accionID == 7 || a.accionID == 8);

In general, if you find yourself writing:

if (x) {
    return true;
} else {
    return false;
}

then:

1. If x is already a boolean, you can do just

   return x;
   

2. If x is not necessarily boolean (and it matters that you return a boolean, specifically), you can use the !! idiom to make it a boolean:

   return !!x;
   

Similarly, if you find yourself writing:

if (x) {
    return false;
} else {
    return true;
}

you can always write that as

return !x;

instead.