Closures/Value capture: Difference between revisions
Content added Content deleted
m (added whitespace and highlighting to the task's preamble, used a larger font to show the expressions so that the italics and superscripts are easier to read.) |
|||
| Line 2: | Line 2: | ||
;Task: |
;Task: |
||
Create a list of '''10''' functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index <big><big><math> i </math></big></big> (you may choose to start <big><big><math> i </math></big></big> from either '''0''' or '''1'''), when run, should return the square of the index, that is, <big><big><math> i^2</math></big></big>. |
|||
Create a list of 10 functions, in the simplest manner possible |
|||
(anonymous functions are encouraged), such that the function at index <big><math> i </math></big> |
|||
(you may choose to start <big><math> i </math></big> from either 0 or 1), when run, |
|||
should return the square of the index, that is, <big><math>i^2</math></big>. |
|||
Display the result of running any but the last function, |
Display the result of running any but the last function, to demonstrate that the function indeed remembers its value. |
||
to demonstrate that the function indeed remembers its value. |
|||
| Line 16: | Line 12: | ||
In imperative languages, one would generally use a loop with a mutable counter variable. |
In imperative languages, one would generally use a loop with a mutable counter variable. |
||
For each function to maintain the correct number, it has to capture the ''value'' |
For each function to maintain the correct number, it has to capture the ''value'' of the variable at the time it was created, rather than just a reference to the variable, which would have a different value by the time the function was run. |
||
of the variable at the time it was created, rather than just a reference to the variable, which would have a different value by the time the function was run. |
|||
<br><br> |
<br><br> |
||