A better vanilla JS approach to finding any false value in a nested object?

You could take the valus from the object and iterate with a short circuit.

const 
    hasTrue = object => Object
        .values(object)
        .some(v => v === false || v && typeof v === 'object' && hasTrue(v)),
    object = { field1: { subfield1: true, subfield2: true }, field2: { subfield3: true }, field3: { subfield4: false, subfield5: true } };

console.log(hasTrue(object));

With suggested check object in advance

const 
    hasTrue = value => value === true || !!value && typeof value === 'object' && Object
        .values(value)
        .some(hasTrue),
    object = { field1: { subfield1: true, subfield2: true }, field2: { subfield3: true }, field3: { subfield4: false, subfield5: true } };

console.log(hasTrue(object));

Here is a simple recursive solution that uses Object.values,flat and some.

function toValues (obj) {
    if (typeof obj === 'object') return Object.values(obj).map(toValues);
    return obj;
}
const findFalse = obj => toValues(obj).flat().some(v => v === false)

const res = findFalse(obj);

console.log (res);
<script>
const obj = {
  field1: {
    subfield1: true,
    subfield2: true,
  },
  field2: {
    subfield3: true,
  },
  field3: {
    subfield4: false,
    subfield5: true,
  }
}
</script>

If there's arbitrary nesting, you can't avoid recursion. You can make it cleaner though:

const isObj = obj => obj && typeof obj == "object";
const findFalseRecursively = val => {
  if (val === false)
    return true;
  if (isObj(val))
    for (const field in val) {
      if (findFalseRecursively(val[field]))
        return true;
  return false;
}

You could do it by searching inside the string representation of the object like so:

const o = {
  field1: {
    subfield1: true,
    subfield2: true,
  },
  field2: {
    subfield3: true,
  },
  field3: {
    subfield4: false,
    subfield5: true,
  }
};

const containsFalse = (obj) => /\".+\"\:false[^\"]/.test(JSON.stringify(obj));

console.log(containsFalse(o));
console.log(containsFalse({a:":false"}));

JSON.stringify(...) is pretty costly though, so I don't know if this is an improvement performance wise.

Update: It is a bit slower than other methods shown here, but if you need something simple it might still be useful. https://jsbench.me/4akcx6gxsn/1

Tags:

Javascript

Recent Posts