Pascal - User input name of array











up vote
0
down vote

favorite












I’m writing a Lazarus application that selects and manipulates data contained in a particular two-dimensional array specified by the user, from a number of preset two-dimensional arrays. My problem is that I don’t know how to convert the user input string into an array name.



An example application contains three two-dimensional arrays:
aaa, bbb and ccc. I want the user to enter, say, bbb and the index (i) in two edit boxes, then be able to read the data contained in bbb[i,2] and bbb[i,3].



...
type
table = array [1..10, 1..3] of real;

var
aaa, bbb, ccc : table;
Duration : real;
i : integer;
Sector : string[3];

...
procedure SetUpTables;
{code that puts data into aaa, bbb, and ccc}
end;
...

{Code that asks user to input aaa, bbb or ccc into Edit1.Text}

...
procedure TForm1.Edit1Exit(Sender: Tobject)
Sector := Edit1.Text;
Duration := Sector[i,3];
end;
...


In the last procedure, I want to use the contents of Sector (aaa, bbb or ccc) to access bbb[i,3]. As you would imagine, I get an “illegal qualifier” error in the line “Duration := Sector[1,3];” at the second index for Sector.



I’m afraid I can’t see how to use the contents of Sector as the array name. I would be grateful for any thoughts on how this can be done.










share|improve this question






















  • In Pascal, variable names are discarded durng the compilation process. You need to write a function which accepts the name the user has input and returns the array (or a pointer to it) that (by whatever criteria you choose) matches the name, or some other value (e.g. Nil) if no match is found. You will learn far more if you work out how to do this yourself rather than just have someone post code which does it.
    – MartynA
    Nov 22 at 17:47










  • Thanks MartynA. I would like to solve the issue myself, and was thinking about pointers. I’ll carry on trying to resolve it along the lines you suggest.
    – tuskerknee
    Nov 22 at 17:54












  • Good. Try your best, and if you get stuck on the coding, by all means come back and post a new q, including your code so far.
    – MartynA
    Nov 22 at 17:56

















up vote
0
down vote

favorite












I’m writing a Lazarus application that selects and manipulates data contained in a particular two-dimensional array specified by the user, from a number of preset two-dimensional arrays. My problem is that I don’t know how to convert the user input string into an array name.



An example application contains three two-dimensional arrays:
aaa, bbb and ccc. I want the user to enter, say, bbb and the index (i) in two edit boxes, then be able to read the data contained in bbb[i,2] and bbb[i,3].



...
type
table = array [1..10, 1..3] of real;

var
aaa, bbb, ccc : table;
Duration : real;
i : integer;
Sector : string[3];

...
procedure SetUpTables;
{code that puts data into aaa, bbb, and ccc}
end;
...

{Code that asks user to input aaa, bbb or ccc into Edit1.Text}

...
procedure TForm1.Edit1Exit(Sender: Tobject)
Sector := Edit1.Text;
Duration := Sector[i,3];
end;
...


In the last procedure, I want to use the contents of Sector (aaa, bbb or ccc) to access bbb[i,3]. As you would imagine, I get an “illegal qualifier” error in the line “Duration := Sector[1,3];” at the second index for Sector.



I’m afraid I can’t see how to use the contents of Sector as the array name. I would be grateful for any thoughts on how this can be done.










share|improve this question






















  • In Pascal, variable names are discarded durng the compilation process. You need to write a function which accepts the name the user has input and returns the array (or a pointer to it) that (by whatever criteria you choose) matches the name, or some other value (e.g. Nil) if no match is found. You will learn far more if you work out how to do this yourself rather than just have someone post code which does it.
    – MartynA
    Nov 22 at 17:47










  • Thanks MartynA. I would like to solve the issue myself, and was thinking about pointers. I’ll carry on trying to resolve it along the lines you suggest.
    – tuskerknee
    Nov 22 at 17:54












  • Good. Try your best, and if you get stuck on the coding, by all means come back and post a new q, including your code so far.
    – MartynA
    Nov 22 at 17:56















up vote
0
down vote

favorite









up vote
0
down vote

favorite











I’m writing a Lazarus application that selects and manipulates data contained in a particular two-dimensional array specified by the user, from a number of preset two-dimensional arrays. My problem is that I don’t know how to convert the user input string into an array name.



An example application contains three two-dimensional arrays:
aaa, bbb and ccc. I want the user to enter, say, bbb and the index (i) in two edit boxes, then be able to read the data contained in bbb[i,2] and bbb[i,3].



...
type
table = array [1..10, 1..3] of real;

var
aaa, bbb, ccc : table;
Duration : real;
i : integer;
Sector : string[3];

...
procedure SetUpTables;
{code that puts data into aaa, bbb, and ccc}
end;
...

{Code that asks user to input aaa, bbb or ccc into Edit1.Text}

...
procedure TForm1.Edit1Exit(Sender: Tobject)
Sector := Edit1.Text;
Duration := Sector[i,3];
end;
...


In the last procedure, I want to use the contents of Sector (aaa, bbb or ccc) to access bbb[i,3]. As you would imagine, I get an “illegal qualifier” error in the line “Duration := Sector[1,3];” at the second index for Sector.



I’m afraid I can’t see how to use the contents of Sector as the array name. I would be grateful for any thoughts on how this can be done.










share|improve this question













I’m writing a Lazarus application that selects and manipulates data contained in a particular two-dimensional array specified by the user, from a number of preset two-dimensional arrays. My problem is that I don’t know how to convert the user input string into an array name.



An example application contains three two-dimensional arrays:
aaa, bbb and ccc. I want the user to enter, say, bbb and the index (i) in two edit boxes, then be able to read the data contained in bbb[i,2] and bbb[i,3].



...
type
table = array [1..10, 1..3] of real;

var
aaa, bbb, ccc : table;
Duration : real;
i : integer;
Sector : string[3];

...
procedure SetUpTables;
{code that puts data into aaa, bbb, and ccc}
end;
...

{Code that asks user to input aaa, bbb or ccc into Edit1.Text}

...
procedure TForm1.Edit1Exit(Sender: Tobject)
Sector := Edit1.Text;
Duration := Sector[i,3];
end;
...


In the last procedure, I want to use the contents of Sector (aaa, bbb or ccc) to access bbb[i,3]. As you would imagine, I get an “illegal qualifier” error in the line “Duration := Sector[1,3];” at the second index for Sector.



I’m afraid I can’t see how to use the contents of Sector as the array name. I would be grateful for any thoughts on how this can be done.







arrays pascal lazarus






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Nov 22 at 17:22









tuskerknee

11




11












  • In Pascal, variable names are discarded durng the compilation process. You need to write a function which accepts the name the user has input and returns the array (or a pointer to it) that (by whatever criteria you choose) matches the name, or some other value (e.g. Nil) if no match is found. You will learn far more if you work out how to do this yourself rather than just have someone post code which does it.
    – MartynA
    Nov 22 at 17:47










  • Thanks MartynA. I would like to solve the issue myself, and was thinking about pointers. I’ll carry on trying to resolve it along the lines you suggest.
    – tuskerknee
    Nov 22 at 17:54












  • Good. Try your best, and if you get stuck on the coding, by all means come back and post a new q, including your code so far.
    – MartynA
    Nov 22 at 17:56




















  • In Pascal, variable names are discarded durng the compilation process. You need to write a function which accepts the name the user has input and returns the array (or a pointer to it) that (by whatever criteria you choose) matches the name, or some other value (e.g. Nil) if no match is found. You will learn far more if you work out how to do this yourself rather than just have someone post code which does it.
    – MartynA
    Nov 22 at 17:47










  • Thanks MartynA. I would like to solve the issue myself, and was thinking about pointers. I’ll carry on trying to resolve it along the lines you suggest.
    – tuskerknee
    Nov 22 at 17:54












  • Good. Try your best, and if you get stuck on the coding, by all means come back and post a new q, including your code so far.
    – MartynA
    Nov 22 at 17:56


















In Pascal, variable names are discarded durng the compilation process. You need to write a function which accepts the name the user has input and returns the array (or a pointer to it) that (by whatever criteria you choose) matches the name, or some other value (e.g. Nil) if no match is found. You will learn far more if you work out how to do this yourself rather than just have someone post code which does it.
– MartynA
Nov 22 at 17:47




In Pascal, variable names are discarded durng the compilation process. You need to write a function which accepts the name the user has input and returns the array (or a pointer to it) that (by whatever criteria you choose) matches the name, or some other value (e.g. Nil) if no match is found. You will learn far more if you work out how to do this yourself rather than just have someone post code which does it.
– MartynA
Nov 22 at 17:47












Thanks MartynA. I would like to solve the issue myself, and was thinking about pointers. I’ll carry on trying to resolve it along the lines you suggest.
– tuskerknee
Nov 22 at 17:54






Thanks MartynA. I would like to solve the issue myself, and was thinking about pointers. I’ll carry on trying to resolve it along the lines you suggest.
– tuskerknee
Nov 22 at 17:54














Good. Try your best, and if you get stuck on the coding, by all means come back and post a new q, including your code so far.
– MartynA
Nov 22 at 17:56






Good. Try your best, and if you get stuck on the coding, by all means come back and post a new q, including your code so far.
– MartynA
Nov 22 at 17:56



















active

oldest

votes











Your Answer






StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53435787%2fpascal-user-input-name-of-array%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown






























active

oldest

votes













active

oldest

votes









active

oldest

votes






active

oldest

votes
















draft saved

draft discarded




















































Thanks for contributing an answer to Stack Overflow!


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


To learn more, see our tips on writing great answers.





Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


Please pay close attention to the following guidance:


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53435787%2fpascal-user-input-name-of-array%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

What visual should I use to simply compare current year value vs last year in Power BI desktop

Alexandru Averescu

Trompette piccolo