Iterating through a filtered list returns undefined

Question

Can someone explain why harvesters[i] would return undefined in this case? I've used similar code before with no issues. This is for the game Screeps.

  var harvesters=_(Game.creeps).filter( { memory: { role: 'harvester' } } );

  for(var i in harvesters)
  {
    //console.log(harvesters[i]); //this is the debug code I mention below
    harvesters[i].memory.sourceid=0;
  }
}

After some testing (thanks to the comments) I found that harvesters[i] did not return the harvester object I expected.... each harvester is apparently an instance of

function wrapperValue() {
      return baseWrapperValue(this.__wrapped__, this.__actions__);
    }

when I try outputting it to console. Why isnt this a creep object?

Answer 1

You're currently using lodash's chained sequence functionality, in order to extract the unwrapped value you'll need to call .value().

Your code will have to look somewhat like this:

const harvesters = _(Game.creeps).filter(
  {
    memory: {
      role: 'harvester'
    }
  }
).value();

Alternatively you can use _.filter directly:

const harvesters = _.filter(Game.creeps, {
  memory: {
    role: 'harvester'
  }
});