Increment and Decrement Operators

Arguments

Returns

The value of the symbol plus or minus one.

Description

These operators perform auto-increments or decrements on numeric symbols. When the ++ is placed before a symbol, it performs a pre-increment, where the value is incremented and the result is the symbol's value + 1. When ++ is placed after a symbol, it performs a post-increment. Here the result of the operation is the value of the symbol prior to being incremented. The -- operator works in the same way. These operators only take symbols as arguments. It is not possible to auto-increment or decrement an array element, list element, or instance variable.

Examples

    Gamma> a = 5;
    5
    Gamma> ++ a;
    6
    Gamma> a;
    6
    Gamma> a ++;
    6
    Gamma> a;
    7
    Gamma> a = 5;
    5
    Gamma> -- a;
    4
    Gamma> a;
    4
    Gamma> a --;
    4
    Gamma> a;
    3
    Gamma>