Variables#

Introduction #

The Variables blocks in VEXcode AIM allow for storing and managing data, including numbers, Boolean values, lists, and 2D lists.

To make a variables blocks appear you must first create a variable. Variables are created using the Make buttons in the Variables category. All variables are global by default, meaning they can be used anywhere in the project.

Below is a list of available blocks:

Numeric Variables - Store and modify numbers.

numeric variable – Returns the value of a numeric variable.
set numeric variable – Assigns a value to a numeric variable.
change numeric variable – Increases or decreases a numeric variable by a set amount.

Boolean Variables – Store True or False values.

Boolean variable – Returns the value of a Boolean variable.
set Boolean variable – Assigns a True or False value to a Boolean variable.

Lists – Store and manage collections of values.

list item – Returns a value from a list based on its position.
replace list item – Updates a specific item in a list.
set list items – Assigns values to a list.
length of list – Returns the number of items in a list.

2D Lists – Store and manage collection of values in a grid.

2D list item – Returns a value from a specific row and column in a 2D list.
replace 2D list item – Updates a specific item in a 2D list.
set 2D list items – Assigns values to a 2D list.
length of 2D list – Returns the number of rows or columns in a 2D list.

numeric variable #

The numeric variable reporter block is used to return the numeric value assigned to the variable.

The Numeric variable reporter block.#

    (my_variable)

Parameter	Description
	This block has no parameters.

Example

  when started :: hat events
  [Display the value of the variable plus two.]
  set [my_variable v] to [2]
  print ((my_variable) [math_plus v] [2]) on screen ▶

set numeric variable #

The set numeric variable block assigns a value to a numeric variable.

Parameter	Description
variable	The numeric variable to assign a value to. Users can select an existing variable, rename it, or delete it.
value	The number assigned to the variable (can be a whole number, decimal, or numeric block).

Example

  when started :: hat events
  [Set a variable to 10 and display it.]
  set [my_variable v] to [10]
  print (my_variable) on screen ▶

change numeric variable #

The change numeric variable block increases or decreases a variable’s value by a given amount.

The Change Numeric Variable stack block.#

    change [my_variable v] by (1)

Parameter	Description
variable	The numeric variable to modify. Users can select an existing variable, rename it, or delete it.
value	The amount to increase or decrease the variable by.

Example

  when started :: hat events
  [Increase the variable by 5 and display it.]
  set [my_variable v] to [10]
  change [my_variable v] by [5]
  print (my_variable) on screen ▶

Boolean variable #

The Boolean variable block is used to return either a True or False value.

The Boolean Variable reporter block.#

    <my_boolean>

Parameter	Description
	This block has no parameters.

Example

  when started :: hat events
  [Display a message if the variable is set to True.]
  set [my_boolean v] to <true v>
  if <my_boolean> then
  print [Boolean is True!] on screen ▶
  end

set Boolean variable #

The set Boolean variable block assigns a True or False value to a Boolean variable.

The Set Boolean Variable stack block.#

    set [my_boolean v] to <true v>

Parameter	Description
variable	The Boolean variable to assign a value to. Users can select an existing variable, rename it, or delete it.
value	A Boolean value (True or False).

Example

  when started :: hat events
  [Display different messages based on the Boolean value.]
  set [my_boolean v] to <true v>
  if <my_boolean> then
    print [It's true!] on screen ▶
  else
    print [That's false...] on screen ▶
  end

list item #

The list item block is used to return the value of an item in a list.

The List Item reporter block.#

    (item (1) of [my_list v])

Parameter	Description
index	The position of the item in the list (starting at 1).
variable	The list variable to return an item from. Users can select an existing list, rename it, or delete it.

Example

  when started :: hat events
  [Display the second item from a list.]
  set [my_list v] to [Robot] [Orange Barrel] [Blue Barrel]
  print (item (2) of [my_list v]) on screen ▶

replace list item #

The replace list item block updates a specific item in a list.

The Replace List Item stack block.#

    replace item (1) of [my_list v] to (1)

Parameter	Description
variable	The list variable containing the item to modify. Users can select an existing list, rename it, or delete it.
index	The position of the item in the list (starting at 1).
value	The new value assigned to the specified list item.

Example

  when started :: hat events
  [Replace the first item in a list with "Sports Ball".]
  set [my_list v] to [Robot] [Orange Barrel] [Blue Barrel]
  replace item (1) of [my_list v] to [Sports Ball]
  print (item (1) of [my_list v]) on screen ▶

set list items #

The set list items block sets every item in the list to the entered values.

The Set List Items stack block.#

    set [my_list v] to [0] [0] [0]

Parameter	Description
variable	The list variable being assigned values. Users can select an existing list, rename it, or delete it.
values	The values to store in the list, entered as individual items.

Example

  when started :: hat events
  [Display the last item in a list.]
  set [my_list v] to [Red] [Green] [Blue]
  print (item (3) of [my_list v]) on screen ▶

length of list #

The length of list block returns the number of items in a list.

The Length of List reporter block.#

    (length of [my_list v])

Parameter	Description
variable	The list variable to return the length of. Users can select an existing list, rename it, or delete it.

Example

  when started :: hat events
  [Display how many items are in a list.]
  set [my_list v] to [Red] [Green] [Blue]
  print (length of [my_list v]) on screen ▶

2D list item #

The 2D list item block is used to return the value of an item in a 2D list.

The 2D List Item reporter block.#

    (item (1) (1) of [my_2d_list v])

Parameter	Description
row	The row of the item (starting at 1).
column	The column of the item (starting at 1).
variable	The 2D list variable to return an item from. Users can select an existing 2D list, rename it, or delete it.

Example

  when started :: hat events
  [Display an item from a 2D list.]
  set [my_2d_list v] to ([1][Orange Barrel]) ([2][Blue Barrel]) 
  print (item (2) (2) of [my_2d_list v]) on screen ▶

replace 2D list item #

The replace 2D list item block updates a specific item in a 2D list.

The Replace 2D List Item stack block.#

    replace item (1) (1) of [my_2d_list v] to (1)

Parameter	Description
row	The row index of the item (starting at 1).
column	The column index of the item (starting at 1).
variable	The 2D list variable containing the item to modify. Users can select an existing 2D list, rename it, or delete it from the drop-down menu.
value	The new value assigned to the specified 2D list item.

Example

  when started :: hat events
  [Replace a value in a 2D list and print the updated item.]
  set [my_2d_list v] to ([1][Orange Barrel]) ([3][Blue Barrel]) 
  replace item [2] [2] of [my_2d_list v] to [Sports Ball]
  print (item (2) (2) of [my_2d_list v]) on screen ▶

set 2D list items #

The set 2D list items block sets every item in the 2D list to the entered values.

The Replace 2D List Item stack block.#

    set [my_2d_list v] to ([0][0]) ([0][0])

Parameter	Description
variable	The 2D list variable being assigned values. Users can select an existing 2D list, rename it, or delete it.
values	The values to store in the 2D list, entered row by row.

Example

  when started :: hat events
  [Display an item from a 2D list.]
  set [my_2d_list v] to ([1][Orange Barrel]) ([2][Blue Barrel]) 
  print (item (1) (2) of [my_2d_list v]) on screen ▶

length of 2D list #

The length of 2D list block reports the number of rows or columns in a 2D list.

The Length of 2D List reporter block.#

    length of [my_2d_list v] [rows v]

Parameter	Description
variable	The 2D list variable to check the length of. Users can select an existing 2D list, rename it, or delete it.
rows/columns	Whether to return the number of rows or column.

Example

  when started :: hat events
  [Set a 2D list and print the number of rows it has.]
  set [my_2d_list v] to ([1][Orange Barrel]) ([3][Blue Barrel]) 
  print (length of [my_2d_list v] [rows v]) on screen ▶