Recursive Contains

recursive_contains.js

// solution to problem #6 in recursive exercises
function contains(object, searchValue) {
  // because `null` has a typof "object", we have to explicitly check
  // to prevent trying to access `null`'s values (which don't exist)
  if (typeof object !== "object" || object === null) {
    return object === searchValue;
  }

  for (const value of Object.values(object)) {
    // An important problem in the code quiz solution is that `return contains()` will only
    // search the first property of an object, as it will return whatever the result for it is.
    // If our value was nested within the second property, for example, it would never get checked
    // even if the first nested object did not contain it.
    if (contains(value, searchValue)) {
      return true;
    }
  }
  return false;
}

function nested(objeto, item) {
for (let key in objeto) {
if (objeto[key] === item) {
return true;
}
if (typeof objeto[key] === 'object') {
if (nested(objeto[key], item)) {
return true;
}
}
}
return false;
}

Can I get an iterative approach?

Just adding another recursive solution here that utilizes Array.prototype.some, nice and succinct:

function contains(obj, targetValue) {
  if (typeof obj !== 'object' || obj === null) return false;

  return Object.values(obj).some(
    (value) => value === targetValue || contains(value, targetValue),
  );
}

I had originally used a ternary statement (below) as the callback for .some(), which felt a bit easier to read to me, but for the sake of keeping it short, modified to the above.

function contains(obj, targetValue) {
  if (typeof obj !== 'object' || obj === null) return false;

  return Object.values(obj).some((value) =>
    value === targetValue  ? true : contains(value, targetValue),
  );
}