Timeline for Flood game implementation
Current License: CC BY-SA 3.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 21, 2014 at 1:23 | history | edited | Flambino | CC BY-SA 3.0 |
clarification
|
| Oct 20, 2014 at 20:37 | vote | accept | kharandziuk | ||
| Oct 20, 2014 at 20:37 | vote | accept | kharandziuk | ||
| Oct 20, 2014 at 20:37 | |||||
| Oct 20, 2014 at 20:34 | comment | added | Flambino | @kharandziuk No prob. Added a link to a (simplified) refactored version - just for fun | |
| Oct 20, 2014 at 20:32 | history | edited | Flambino | CC BY-SA 3.0 |
added 75 characters in body
|
| Oct 20, 2014 at 20:11 | comment | added | Flambino |
@kharandziuk The semantics aren't the same. If you just use foo?, yes, you get a boolean. But, as I quoted from the docs in my earlier comment, the ?. (or in this case ?[]) operator is a variant of that. Something like foo?.bar should be read as "if foo? is true (i.e. foo exists), then access foo's bar property"
|
|
| Oct 20, 2014 at 20:05 | comment | added | kharandziuk |
Maybe, I don't understand something: grid[i]? # check that i-th element exists and returns bool and grid[i]?[j] # takes j-th element of bool How does it work?
|
|
| Oct 20, 2014 at 19:51 | comment | added | Flambino |
@kharandziuk And yes, it's very nice - when it makes sense. For instance, let's say you want to print a Person object with an optional lastName property, and you want to make the last name uppercase. Then you could do person.lastName?.toUpperCase(). It's just a shorthand for first checking, and then using a property. Check the docs under "The existential operator": "The accessor variant of the existential operator ?. can be used to soak up null references in a chain of properties"
|
|
| Oct 20, 2014 at 19:45 | comment | added | Flambino |
@kharandziuk ? "absorbs" null/undefined. If you just write @grid[-1][-2] (or some other invalid coordinates) you'll get an error, because @grid[-1] is undefined, and you can't say undefined[-2]. But the ? will protect you from that. In plain JS, it could be written as square = this.grid[i] ? this.grid[i][j] : null followed by if(!square) return
|
|
| Oct 20, 2014 at 19:35 | comment | added | kharandziuk |
Thanks! It's a really nice answer. But: square = @grid[i]?[j] return unless square? looks like magic for me. Is it really nice to use those magic features of a language?
|
|
| Oct 20, 2014 at 19:31 | history | answered | Flambino | CC BY-SA 3.0 |