What Is a Slot?

The slot is a narrow opening on a machine. Slot machines accept paper tickets with barcodes. They spin the reels and offer a jackpot. Most machines also offer variable credits. When a symbol lines up on a payline, the winning combinations are listed on the machine’s pay table.

Slots are also called expansion slots. These include PCI slots, memory slots, and ISA slots.

Slots are an element in Web Components’ technology suite. This allows you to add separate DOM trees to your web application.

Slots are a component of the QObject::connect() macro. Connecting a signal to a slot is done by using the SLOT and SIGNAL macros.

Slots are relatively slow when compared to callbacks. However, it can be useful to use them. In some cases, you may be able to avoid having to call receivers directly. If a signal is emitted from a class that does not have a class definition for the slots, the private slot will be invoked in an unrelated class.

If a slot is emitted from a class that is not defined to be a slot, the slot will report a runtime error. But the slot will still perform its normal C++ rules when called directly.

A slot receiver can be as many as three on the field at once. For example, a player can slap a shot from the high slot into the net or from the low slot, directly in front of the goaltender.