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Pick Random () to () | |

pick random () to () | |

Category |
Operators |

Type |
Reporter |

Introduced in |
11Oct03 |

The **pick random () to ()** block is an operators block and a reporter block. The block returns a pseudorandom number ranging from the first given number to the second, including both endpoints. If both numbers are integers, the number returned will also be an integer. For example, if a 1 and a 3 were the bounds, the block might return either a 1, 2 or 3. If one or both of the number is a float, the number returned will be a double. For example, if 0.1 and 0.14 were given, the output could be any number between 0.1 and 0.14, with up to 17 digits after the decimal point (e.g. 0.13545101673985742).

## Example Uses

Some common uses for the pick random () to () block are:

- Creating randomized levels

when I receive [generate v] go to x: (-50) y: (50) set [square v] to [1] repeat (121) replace item (square) of [level v] with (pick random (1) to (10)) change [square v] by (1) end set [square v] to [1] repeat (11) repeat (11) switch costume to (item (square) of [level v]) stamp change x by (10) change [square v] by (1) end go to x: (-50) y: ((y position) - (10)) end repeat until <not <(item (start) of [level v]) = [10]>> set [start v] to (pick random (1) to (121)) end switch costume to [player v] set [square v] to [1] go to x: (-50) y: (50) repeat until <(square) = (start)> if <(x position) = [50]> then go to x: (-50) y: ((y position) - (10)) else change x by (10) end change [square v] by (1) end broadcast [play v]

- Setting random stats

set [hp v] to (pick random (25) to (100) )

- Choosing random objects

set [purchase v] to (item (pick random (1) to (9) ) of [grocery list v])

switch costume to (pick random (1) to (7))

- Performing an action with a certain probabiltity

if <(pick random (1) to (10)) = (1)> then ... end

## Workaround

*Main article: List of Block Workarounds*

To work around this block, the Scratcher must program a script that will give unpredictable numbers.

A simple workaround is to fill a list with the possible numbers, and then use the Item () of () block with the first input set to *any* or *random*. The Item (random) of () block chooses an unpredictable item — so if the chosen list has all the wanted numbers, the Item () of () block is an effective workaround:

when green flag clicked set [random number v] to (item (join [random] () ) of [list v] )

There are scripts that can return unpredictable numbers without using any blocks that give random values. To make these scripts, a value must be used that is unpredictable, such as the timer. Other choices are:

- Continuously moving a hidden sprite around the screen and using its location
- Continuously changing a variable and using its current value
- Continuously changing the pen color, shade or size and using its value

Then a script can be created with the value, an example with a continuously moving sprite:

set [random number v] to (x position)

This, however, is rather simple. More complicated scripts can be made:

set [random number v] to ((x position) + (y position))

set [random number v] to ( round ( ( (y position) + ( (direction) * (2) ) ) / (3) ) )

Note: | The random numbers generated from these alternatives may not be as accurate as the Pick Random () to () block. |

() + ()
• () - () • () * () • () / () • Pick Random () to () • () < () • () = () • () > () • () and () • () or () • Not () • Join ()() • Letter () of () • Length of () • () Mod () • Round () • () of ()More blocks... |