What action is performed by the operation of increasing a variable's value by one in a programming language?

The operation of increasing a variable's value by one is called an increment. In programming languages like Swift (iOS), this is usually expressed with the ++ operator (in older versions) or using the addition assignment variable += 1.

Increment increases the current value of the variable by 1. For example:

var count = 5
count += 1 // count is now 6

This is often used in loops, counters, and when working with indices.