The only way to truly test if a variable is undefined is to do the following. Remember, undefined is an object in Javascript. To determine if a variable or object property exists, It is good to compare to keyword undefined or you can also check the type of the object to string âundefinedâ. In the following JavaScript code we compare the num to the undefined in both way.
Nuclear waste -- The waste from nuclear power plants will be toxic for humans for more than 100,000 years. Itâs untenable now to secure and store all of the waste from the plants that exist. To scale up to 2,500 or 3,000, let alone 17,000 plants is unthinkable.
That's lightningâand you don't want to be anywhere near it when it strikes. Humans are good conductors. Being comprised of atoms that can transmit electrons is great for our neural network's basic functionality. But it's very bad when we drop a hairdryer in the tub, crack open an industrial capacitor, or become a human lightning rod on the links. Lightning strikes do, however, differ from the industrial shocks you'd receive from high-voltage equipment.