Timeline for How to use Or (||) in a less verbose test function?
Current License: CC BY-SA 4.0
18 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 12 at 10:43 | answer | added | Sjoerd Smit | timeline score: 6 | |
| Nov 12 at 8:16 | answer | added | Roman | timeline score: 5 | |
| Nov 9 at 22:39 | vote | accept | Andrew | ||
| Nov 9 at 22:39 | history | became hot network question | |||
| Nov 9 at 17:26 | review | Close votes | |||
| Nov 12 at 20:32 | |||||
| Nov 9 at 17:17 | comment | added | Michael E2 |
Perhaps I misread?: If you wish a list of True/False, then what's wrong with Map[MatchQ["A" | "a"]]@myStrList? I suppose your question is really just about what Or[] means and how it works in Mathematica. Have you looked at the documentation, because its evaluation to only True or False is clearly stated at the top; hence, it cannot be equal to a string.
|
|
| Nov 9 at 13:53 | comment | added | Michael E2 |
Or[] is not way represent alternative values. It's a logical connective to connect boolean expressions (whose value is presumed to be from the set {True, False}). Since a string does not represent a boolean expression, Mathematica does not know what to do with it and leaves it alone. About the only evaluation one can get is ("a" || "A") == ("A" || "a") since each side is identical. Now Or could connect to equalities, as in Thread[# == ("A" || "a"), Or] & /@ myStrList.
|
|
| Nov 9 at 13:48 | answer | added | creidhne | timeline score: 4 | |
| Nov 9 at 13:42 | comment | added | Michael E2 |
@Nasser's suggestion of AnyTrue[] will "create a function that will return True..." as you say you want. Further, it will return True as soon as it runs into an "a" or an "A", whereas Map[] will pointlessly continue to check all remaining strings.
|
|
| Nov 9 at 11:28 | answer | added | Domen | timeline score: 5 | |
| Nov 9 at 11:01 | answer | added | azerbajdzan | timeline score: 5 | |
| Nov 9 at 2:12 | comment | added | Bob Hanlon |
Or, ToUpperCase[#] == "A" & /@ myStrList
|
|
| Nov 9 at 1:59 | comment | added | Syed |
StringMatchQ["A" | "a"]@myStrList ?
|
|
| Nov 8 at 22:15 | comment | added | lericr |
If by "condense" you mean something more like "reduce duplicated constructs", then you could do a variety of things. E.g. test = (Apply[Or]@*Comap[MatchQ /@ {"A", "a"}]). To demonstrate, test["A"] gives True and test["b"] gives False.
|
|
| Nov 8 at 22:03 | comment | added | lericr |
If you specifically want Or in your test, then no, I don't think there's a way to condense your test. Or expects to be applied to boolean expressions. The expression Or["A", "a"] is applying Or to strings. The semantic that you're looking for in something like Or["A", "a"] is already provided by Alternatives, which you've already used successfully in another version of your test.
|
|
| Nov 8 at 21:12 | comment | added | Nasser |
# == Or["A", "a"] & does not look right to me. The syntax of Or is not like this. But why not just use something like AnyTrue[myStrList,Or[#=="A",#=="a"]&]. I know you said you wanted to use Map. In Mathematica there are many ways to do the same thing. I see nothing wrong with your earlier tries also. But the last one, your Or usage is not correct. You can fix it by doing Or[# == "A", # == "a"] i.e. move the # inside.
|
|
| Nov 8 at 21:06 | history | edited | Andrew | CC BY-SA 4.0 |
improved formatting
|
| Nov 8 at 21:01 | history | asked | Andrew | CC BY-SA 4.0 |