m (updated to 3.0 sb)
(→‎Offline decimal trick: Updated information)
 
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|category = [[Operators Blocks|Operators]]
 
|category = [[Operators Blocks|Operators]]
 
|type = [[Reporter Block|Reporter]]
 
|type = [[Reporter Block|Reporter]]
|defaults = "hello "; "world"
+
|defaults = "apple "; "banana"
 
|argTypes = [[string]]; string
 
|argTypes = [[string]]; string
 
|added = 1.4
 
|added = 1.4
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}}
 
}}
 
The '''Join ()()''' [[Blocks|block]] is an [[Operators Blocks|Operators block]] and a [[Reporter Block|Reporter block]]. The block concatenates, or "links" the two values together and reports the result {{-}} for example, if "hello" and "world" were put in the block, it would report "helloworld". To report "hello world", use either "hello " and "world" or "hello" and " world", with a space.
 
The '''Join ()()''' [[Blocks|block]] is an [[Operators Blocks|Operators block]] and a [[Reporter Block|Reporter block]]. The block concatenates, or "links" the two values together and reports the result {{-}} for example, if "hello" and "world" were put in the block, it would report "helloworld". To report "hello world", use either "hello " and "world" or "hello" and " world", with a space.
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 +
To join three or more values together, drag copies of this block into its inputs.
 +
{{block Frame|blocks=<scratchblocks>join (join (join [] []) []) (join [] [])</scratchblocks>|caption=Joining five strings}}
 +
{{block Frame|blocks=<scratchblocks>join [apple ] (join [banana ] [cherry])</scratchblocks>|caption=Joining three strings}}
  
 
==Example Uses==
 
==Example Uses==
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<scratchblocks>set pen color to (join [0x] (hex input))</scratchblocks>
 
<scratchblocks>set pen color to (join [0x] (hex input))</scratchblocks>
  
===Offline decimal trick===
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===Showing more decimal places in speech bubbles===
In the [[Offline Editor]] (this does not work online!), numbers in variables and speech bubbles usually round to only one decimal place. In some [[project]]s, it is necessary to have more. Placing the calculation in one input of the Join ()() block and leaving the other input empty "magically" reports the number with more decimal places.
+
Results of calculations in [[Say () (block)|speech bubbles]] are normally rounded to only two decimal places. In some [[project]]s, it is necessary to have more. Placing the calculation in one input of the join block and leaving the other input empty reports the number with more decimal places.
 
* The original script:
 
* The original script:
  
 
<scratchblocks>
 
<scratchblocks>
set [number v] to ([sqrt v] of ((item (1 v) of [list v]) * (3)))
+
say ([sqrt v] of ((item (1 v) of [list v]) * (3)))
 
</scratchblocks>
 
</scratchblocks>
  
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<scratchblocks>
 
<scratchblocks>
set [number v] to (join([sqrt v] of ((item (1 v) of [list v]) * (3))) [])
+
say (join([sqrt v] of ((item (1 v) of [list v]) * (3))) [])
 
</scratchblocks>
 
</scratchblocks>
  
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<scratchblocks>
 
<scratchblocks>
set [number v] to (join((round (([10^ v] of (decimal places)::operators) * ([sqrt v] of ((item (1 v) of [list v]) * (3))))) / ([10^ v] of (decimal places)::operators))[])
+
say (join((round (([10^ v] of (decimal places)::operators) * ([sqrt v] of ((item (1 v) of [list v]) * (3))))) / ([10^ v] of (decimal places)::operators))[])
 
</scratchblocks>
 
</scratchblocks>
  
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<scratchblocks>
 
<scratchblocks>
delete (all v) of [final v]
+
delete all of [final v]
 
set [count v] to [0]
 
set [count v] to [0]
 
repeat (length of (insert1))
 
repeat (length of (insert1))
 
change [count v] by (1)
 
change [count v] by (1)
add (letter (count) of (instert1)) to [final v]
+
add (letter (count) of (insert1)) to [final v]
 
end
 
end
 
set [count v] to [0]
 
set [count v] to [0]
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The variable "result" contains the result.
 
The variable "result" contains the result.
 
This works because list reporters join all of the items in a list without spaces if they are all 1 character long, and so by taking just 1 letter from each string at a time and putting them into the list, the reporter has the same result as the join block in most cases.
 
This works because list reporters join all of the items in a list without spaces if they are all 1 character long, and so by taking just 1 letter from each string at a time and putting them into the list, the reporter has the same result as the join block in most cases.
 
==Limitations==
 
The join block displays a phenomenon where it does not output strings longer than 10240 characters, even if either side or both sides of the concatenation are longer than this amount. The characters which are expected to appear beyond the 10240th character are just truncated.<ref>https://scratch.mit.edu/discuss/youtube/XKN8fj_pO4</ref>
 
It is still possible to join two strings to longer than 10240, but it cannot be done with the join block — it must be done using the workaround listed above.
 
  
 
==References==
 
==References==

Latest revision as of 19:57, 21 March 2021

Join ()()
join ()()
Category Operators
Type Reporter
Introduced in 1.4

The Join ()() block is an Operators block and a Reporter block. The block concatenates, or "links" the two values together and reports the result — for example, if "hello" and "world" were put in the block, it would report "helloworld". To report "hello world", use either "hello " and "world" or "hello" and " world", with a space.

To join three or more values together, drag copies of this block into its inputs.

join (join (join [] []) []) (join [] [])
Joining five strings
join [apple ] (join [banana ] [cherry])
Joining three strings

Example Uses

If words, numbers, sentences—any two values—must be concatenated together, this block easily does the job.

Some common uses for the Join ()() block:

  • Joining words and variables to create a sentence
when flag clicked
ask [What's your name?] and wait
say (join (join (join (join [Hello ] (answer))[. My name is ]) (Person's name)) [.])
  • Place a variable in a message (e.g. "You completed 2 loops")
say (join [The score is ] (join (score) [.]))
  • An easy method of negating a positive number
set [variable v] to (join [-] (number))
Note Note: This does not work on numbers that are already negative.
  • Using hex inputs in pen colors
set pen color to (join [0x] (hex input))

Showing more decimal places in speech bubbles

Results of calculations in speech bubbles are normally rounded to only two decimal places. In some projects, it is necessary to have more. Placing the calculation in one input of the join block and leaving the other input empty reports the number with more decimal places.

  • The original script:
say ([sqrt v] of ((item (1 v) of [list v]) * (3)))
  • Script with more decimals:
say (join([sqrt v] of ((item (1 v) of [list v]) * (3))) [])
  • To set the number of decimal places, use a script like this:
say (join((round (([10^ v] of (decimal places)::operators) * ([sqrt v] of ((item (1 v) of [list v]) * (3))))) / ([10^ v] of (decimal places)::operators))[])

Workaround

Main article: List of Block Workarounds

This block can be replicated with the following code:

delete all of [final v]
set [count v] to [0]
repeat (length of (insert1))
change [count v] by (1)
add (letter (count) of (insert1)) to [final v]
end
set [count v] to [0]
repeat (length of (insert2))
change [count v] by (1)
add (letter (count) of (insert2)) to [final v]
end
set [result v] to (final)

The variable "result" contains the result. This works because list reporters join all of the items in a list without spaces if they are all 1 character long, and so by taking just 1 letter from each string at a time and putting them into the list, the reporter has the same result as the join block in most cases.

References


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