Two plus signs raising a value by one.
Two plus signs add one to a variable in place. Whether the operator sits before or after the variable decides whether the expression yields the value before or after the change.
ECMAScript defines both the prefix and postfix forms: each adds one to the operand, and they differ in the value the expression itself produces.
Contexts: Software
Inherited from C, and the language C++ is named for the operator — the name asserts that it is C incremented.
Contexts: Software
Two identical upright crosses side by side, each formed of one horizontal and one vertical stroke of equal length.
The increment operator is the plus sign doubled, and doubling changes it from addition to a modification in place.
Both are used in software contexts.