| Insert () at () of () | |
insert () at () of [ v] | |
| Category | Variables |
| Type | Stack |
| Introduced in | 1.3 |
The Insert () at () of () block is a List block and a Stack block. The block inserts an item containing the given text into the list, at the given position. All values below the inserted item are passed onto the item beneath them; the last item's value is placed in a new item at the end of the list.
Example Uses
If a list is used for holding objects in a special order and an object has to be added, using the Add () to () block would ruin the sequence—this block, however, can insert objects without ruining the order.
Some common uses for the Insert () at () of () block:
- Inserting items into a specific part of a list
ask [Where should I insert it?] and wait insert [pie] at (answer) of [favorite foods v]
- Word processors that record all characters in a list, where a character is being inserted in the middle of a sentence
- Giving more precision than the Add () to () block
Removed Features
Before Scratch 3.0, the block also had a dropdown with the options insert [thing] at (last v) of [list v] and insert [thing] at (random v) of [list v]. To use this in Scratch 3.0, the word "last" or "random" can be copied and pasted into the number field, or using the join () () block.
insert [thing] at (join [last] [] ) of [list v]
Workaround
This block can be replicated in a few ways. One way is to use two lists, with one list being copied to the other:
define insert (text) at (index) of list //run without screen refresh
delete all of [handler v] //this is a list used for adding to the other list
set [i v] to (0)
repeat (length of [list v]) //makes a copy
change [i v] by (1)
add (item (i) of [list v]) to [handler v]
end
delete all of [list v]
set [i v] to (0)
repeat (length of [handler v])
change [i v] by (1)
if <(index) = (i)> then
add (text) to [list v]
end
add (item (i) of [handler v]) to [list v]
end
A workaround is also possible with just one list by recycling the list:
define insert (text) at (index) of list set [i v] to (0) repeat (length of [list v]) change [i v] by (1) if <(index)=(i)> then add (text) to [list v] end add (item (1) of [list v]) to [list v] delete (1) of [list v] end
