() is less than () (block)

The correct title of this article is () < () (block). The Scratch Wiki uses this different title because of technical restrictions.

() < ()
() \< ()
Category	Operators
Type	Boolean
Introduced in	11Oct03

The () < () block is an Operators block and a Boolean block. The block reports true if the first value is less than the second value and false otherwise.

This block can compare both numbers and strings, which are ordered alphabetically. In Scratch 1.3 and previous versions, it only accepted numbers.

Example Uses

Some common uses for the () < () block are below:

• Sorting
• Inserting an item in a sorted list

set [i v] to [1]
repeat until <<(i) > (length of [scores v])> or <(item (i) of [scores v]) < (score)>>
    change [i v] by (1)
end
insert (score) at (i) of [scores v]

• Evaluating numbers or letters

if <(score) < (5)> then
    say [Poor job.] for (1) secs
    stop [this script v]
end
if <(item (i) of [scores v]) < (10)> then
    say [Well done.] for (1) secs
    stop [this script v]
end
say [Great!] for (1) secs

• Comparing different variables

if <(score 1) < (score 2)> then
    say [Player 2 wins!]
else
    say [Player 1 wins!]
end

• Checking that a value is within a given range

ask [Please rate my cookies from 1 to 10.] and wait
repeat until <not <<(answer) < [1]> or <(answer) > [10]>>>
    ask [Please rate my cookies from 1 to 10.] and wait
end

Comparison

Comparing Numbers

Numbers will be compared as expected unless they are much larger than their difference:

set [number 1 v] to [100]
set [number 2 v] to [101]
say <(number 1) < (number 2)> for (2) seconds // returns true
set [number 1 v] to [100000000000000000]
set [number 2 v] to [100000000000000001]
say <(number 1) < (number 2)> for (2) seconds // returns false

This can be worked around only if the numbers are stored as strings, which happens if they are typed instead of calculated with Operators blocks.

This example compares numbers stored as strings that do not use a sign, leading zeros, a decimal point, nor scientific notation:

set [number 1 v] to [100000000000000000]
ask [The answer is "100000000000000001"] and wait
set [number 2 v] to (answer)
if <(length of (number 1)) = (length of (number 2))> then
  say <(join (number 1) [a]) < (join (number 2) [a])> for (2) seconds // returns true
else
  say <(length of (number 1)) < (length of (number 2))> for (2) seconds
end

This works because it forces Scratch to do a text comparison instead of a number comparison, which is more accurate at the cost of a small amount of performance.

Comparing Text

Text is compared alphabetically:

<[a] < [b]> // returns true
<[b] < [a]> // returns false

The Empty Value

The empty value will always be considered smaller than other values:

<[] < (10)> // returns true
<(10) < []> // returns false

Workaround

Main article: List of Block Workarounds

The block can be replicated with the following code:

<(b) > (a)>

Less than or equal to

Sometimes it is necessary to know if a value is less than or equal to another value, but there is no block to do so. This can be done as follows:

<not <(a) > (b)>>

See Also

• () = () (block)
• () > ()
• Numbers