Assignment

Assignment

Assignment is done with the equals (=) character.

# Assigns to a local variable
local = 1

# Assigns to an instance variable
@instance = 2

# Assigns to a class variable
@@class = 3

Each of the above kinds of variables will be explained later on.

Some syntax sugar that contains the = character is available:

local += 1  # same as: local = local + 1

# The above is valid with these operators:
# +, -, *, /, %, |, &, ^, **, <<, >>

local ||= 1 # same as: local || (local = 1)
local &&= 1 # same as: local && (local = 1)

A method invocation that ends with = has syntax sugar:

# A setter
person.name=("John")

# The above can be written as:
person.name = "John"

# An indexed assignment
objects.[]=(2, 3)

# The above can be written as:
objects[2] = 3

# Not assignment-related, but also syntax sugar:
objects.[](2, 3)

# The above can be written as:
objects[2, 3]

The = operator syntax sugar is also available to setters and indexers. Note that || and && use the []? method to check for key presence.

person.age += 1        # same as: person.age = person.age + 1

person.name ||= "John" # same as: person.name || (person.name = "John")
person.name &&= "John" # same as: person.name && (person.name = "John")

objects[1] += 2        # same as: objects[1] = objects[1] + 2

objects[1] ||= 2       # same as: objects[1]? || (objects[1] = 2)
objects[1] &&= 2       # same as: objects[1]? && (objects[1] = 2)