If you are always finding yourself in need of an iPhone charger, you can get 3 for $5.99 when you enter the code 406LCCLC at checkout. Go here to order yours.
You will get a 3, 6 and a 10 foot charger.
Keep in mind these do not plug into the USB charger bricks. You need a USB C brick. You can get 3 for $10 here.