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digitalmars.D.learn - User imput string int and float[DOUBT]

reply Jean Cesar <jeanzonta777 yahoo.com.br> writes:
How do I make a class person where I use set and get methods to 
imput the user type:

Import std.stdio;

class person
{
   private:
   string name, address;
   int age;
   float height;

public:
   void setNome()
   {
     write("Enter Your Name:");
     // the problem is here how am I going to read the imput of a 
string typed by the user?
   }

void setIty()
{
    write("Enter Your Age:");
   // Another problem here also to read integer values like I 
would?
}

void setHeight()
{
   write("Enter Your Height:");
   // Another problem here also to read floats or double values 
like I would?
}

float getHeight()
{
   return height;
}

int getIty()
{
   return age;
}

string getNome()
{
   return name;
}

}

void main ()
{
   person p = new person();

   p.setName();
   p.setIdade();
   p.setHeight();

   p.getName();
   p.getIdade();
   p.getHeight();
}
Feb 15 2017
parent reply =?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:
On 02/15/2017 03:20 PM, Jean Cesar wrote:

 How do I make a class person where I use set and get methods to imput
 the user type:


I have some information here:

   http://ddili.org/ders/d.en/input.html

You should also know how to read strings:

   http://ddili.org/ders/d.en/strings.html

And this section about refactoring has the concept of a readInt() 
function template:

   http://ddili.org/ders/d.en/functions.html#ix_functions.refactor

Combining all three:

import std.stdio;
import std.traits;

auto read(T)(ref T t, string message)
if (!isSomeString!T) {
     writef("%s: ", message);
     readf(" %s", &t);
     return t;
}

auto read(S)(ref S s, string message)
if (isSomeString!S) {
     import std.string : strip;
     writef("%s: ", message);
     s = readln().strip();
     return s;
}

class person
{
private:
     string name, address;
     int age;
     float height;

public:
     void setNome()
     {
         read(name, "Enter Your Name");
     }

     void setIty()
     {
         read(age, "Enter Your Age");
     }

     void setHeight()
     {
         read(height, "Enter Your Height");
     }

     float getHeight()
     {
         return height;
     }

     int getIty()
     {
         return age;
     }

     string getNome()
     {
         return name;
     }

}

void main ()
{
     person p = new person();

     p.setNome();
     p.setIty();
     p.setHeight();

     writeln(p.getNome());
     writeln(p.getIty());
     writeln(p.getHeight());
}

Unrelated, a bunch of get/set methods is commonly seen as inferior to a 
design where another piece of code does the reading and makes the object 
after the fact:

person readPerson(File input) {
     // ... parse the input ...
     // Potentially, use the constructor:
     auto p = new person(name, age, /* ... */);
     return p;
}

One reason is the fact that the person may be seen as incomplete and 
unusable unless all fields are set. Again, it's beside the point... :)

Ali
Feb 15 2017
parent reply Jean Cesar <jeanzonta777 yahoo.com.br> writes:
On Wednesday, 15 February 2017 at 23:40:41 UTC, Ali Çehreli wrote:

 On 02/15/2017 03:20 PM, Jean Cesar wrote:

 How do I make a class person where I use set and get methods 
 to imput
 the user type:


 I have some information here:

   http://ddili.org/ders/d.en/input.html

 You should also know how to read strings:

   http://ddili.org/ders/d.en/strings.html

 And this section about refactoring has the concept of a 
 readInt() function template:

   
 http://ddili.org/ders/d.en/functions.html#ix_functions.refactor

 Combining all three:

 import std.stdio;
 import std.traits;

 auto read(T)(ref T t, string message)
 if (!isSomeString!T) {
     writef("%s: ", message);
     readf(" %s", &t);
     return t;
 }

 auto read(S)(ref S s, string message)
 if (isSomeString!S) {
     import std.string : strip;
     writef("%s: ", message);
     s = readln().strip();
     return s;
 }

 class person
 {
 private:
     string name, address;
     int age;
     float height;

 public:
     void setNome()
     {
         read(name, "Enter Your Name");
     }

     void setIty()
     {
         read(age, "Enter Your Age");
     }

     void setHeight()
     {
         read(height, "Enter Your Height");
     }

     float getHeight()
     {
         return height;
     }

     int getIty()
     {
         return age;
     }

     string getNome()
     {
         return name;
     }

 }

 void main ()
 {
     person p = new person();

     p.setNome();
     p.setIty();
     p.setHeight();

     writeln(p.getNome());
     writeln(p.getIty());
     writeln(p.getHeight());
 }

 Unrelated, a bunch of get/set methods is commonly seen as 
 inferior to a design where another piece of code does the 
 reading and makes the object after the fact:

 person readPerson(File input) {
     // ... parse the input ...
     // Potentially, use the constructor:
     auto p = new person(name, age, /* ... */);
     return p;
 }

 One reason is the fact that the person may be seen as 
 incomplete and unusable unless all fields are set. Again, it's 
 beside the point... :)

 Ali


So I'm a beginner in this language and have very little time I 
started I'm interested in apprehending concepts of object 
orientation polymorphism inheritance, multiple inheritance as in 
c ++, but I did not understand how to use constructor in it
Because I simply did.

Class person
{
    person(){}
    ~ Person () {}
}

And error ...
Feb 15 2017
parent reply =?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:
On 02/15/2017 05:49 PM, Jean Cesar wrote:


 So I'm a beginner in this language and have very little time I started
 I'm interested in apprehending concepts of object orientation
 polymorphism inheritance, multiple inheritance as in c ++


D is similar to C++ but also very different.


 but I did not
 understand how to use constructor in it
 Because I simply did.

 Class person
 {
    person(){}
    ~ Person () {}
 }

 And error ...


In D, constructor is always called this():

class Person
{
    this(){}
    ~this() {}
}

void main() {
     auto p = new Person();
}

Ali
Feb 15 2017
parent reply Jean Cesar <jeanzonta777 yahoo.com.br> writes:
On Thursday, 16 February 2017 at 02:17:49 UTC, Ali Çehreli wrote:

 On 02/15/2017 05:49 PM, Jean Cesar wrote:


 So I'm a beginner in this language and have very little time


 I started

 I'm interested in apprehending concepts of object orientation
 polymorphism inheritance, multiple inheritance as in c ++


 D is similar to C++ but also very different.


 but I did not
 understand how to use constructor in it
 Because I simply did.

 Class person
 {
    person(){}
    ~ Person () {}
 }

 And error ...


 In D, constructor is always called this():

 class Person
 {
    this(){}
    ~this() {}
 }

 void main() {
     auto p = new Person();
 }

 Ali




So I used get methods and sets only as initial pattern to 
netender the functioning of the language in relation to some 
concepts of the same I intend to learn it not because it is a new 
language, but I want to understand how to leave a very small code 
with the largest number of Possible functionality type I still do 
not know very well or use constructors in C ++ but I have very 
high potential in a code with multiple inheritance, I think of 
compilers in the case of the code that favors me in reading so I 
would do something like:

void main ()
{
    minhaclasse c = new minhaclasse(string text);
    minhaclasse d = new minhaclasse(int number);

  write("Enter your name: ")
  c.set();

  write("Enter your age: ")
  d.set();
   /*
     the set method would already fetch user i
     imput by mistake for the information automatically
   */

   Writeln
    (
     "\n\tString:", c.get (),
     "\n\tInt:", d.get ()
    );
}

Or something like:



void main ()
{
   string txt;
    Int num;
  write("Enter your name: ")
  minhaclasse(text).set();

  write("Enter your age: ")
  minhaclasse(num).set();

   writeln
    (
     "\n\tString:", minhaclasse(text).print() ;,
     "\n\tInt:", minhaclasse(num).print();
    );
}

I think of object orientation this way to avoid getting rewritten 
many things so I would only define what the set or get would 
return by initializing the constructor only but I have no idea 
how to do that ..

My goal in learning to use languages like Java, C ++, D is with 
the intention of learning the best way to reuse code and 
orienation to objects and also development cross-platform codes 
that will run in standard ansi for, Unix, Linux, Windows, android 
etc. ..
Feb 16 2017
parent reply =?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:
On 02/16/2017 02:05 PM, Jean Cesar wrote:


 So I used get methods and sets only as initial pattern to netender the
 functioning of the language in relation to some concepts of the same


Makes sense...


 how to leave a very small code with the largest number of
 Possible functionality type


I think D is very suitable for that.


 I still do not know very well or use
 constructors in C ++


Understandable: Many coding guidelines eschew doing non-trivial work in 
constructors. They require a member function like obj.initialize(/* ... 
*/) to be called in order to get a functioning object.


 but I have very high potential in a code with
 multiple inheritance


That's going to be a problem because D does not allow multiple inheritance.


 I think of compilers in the case of the code that
 favors me in reading so I would do something like:

 void main ()
 {
    minhaclasse c = new minhaclasse(string text);
    minhaclasse d = new minhaclasse(int number);

  write("Enter your name: ")
  c.set();


So, your minhaclasse is basically ValorLegível (ReadableValue), which 
would not scale because likely it's also writable and movable, etc. And 
that explains why you're looking for multiple inheritance. :)

// NOT valid D (and no, I don't speak Portuguese)
class MinhaValor : ValorLegível, ValorEscrita, ValorMóvel /*, ... */ {
     // ...
}


 void main ()
 {
   string txt;
    Int num;
  write("Enter your name: ")
  minhaclasse(text).set();

  write("Enter your age: ")
  minhaclasse(num).set();

   writeln
    (
     "\n\tString:", minhaclasse(text).print() ;,
     "\n\tInt:", minhaclasse(num).print();
    );
 }

 I think of object orientation this way to avoid getting rewritten many
 things so I would only define what the set or get would return by
 initializing the constructor only but I have no idea how to do that ..


You make it sound as if OOP is for code reuse or for reducing code 
repetition. I think regular functions provide that already.

Unless polymorphism is really beneficial, functional style is 
preferable. Additionally, D has this very useful universal function call 
syntax (UFCS), which makes your use case easy to implement, and which my 
earlier code could have benefited from as well.

import std.stdio;
import std.traits;

auto read(T)(ref T t, string message)
if (!isSomeString!T) {
     writef("%s: ", message);
     readf(" %s", &t);
     return t;
}

auto read(S)(ref S s, string message)
if (isSomeString!S) {
     import std.string : strip;
     writef("%s: ", message);
     s = readln().strip();
     return s;
}

class person
{
private:
     string name, address;
     int age;
     float height;

public:
     static person fromConsole()
     {
         auto p = new person();
         /* UFCS in action: Note how these are not written as
          *    read(p.name, /* ... */)
          */
         p.name.read("Enter Your Name");
         p.age.read("Enter Your Age");
         p.height.read("Enter Your Height");
         return p;
     }

     float getHeight()
     {
         return height;
     }

     int getIty()
     {
         return age;
     }

     string getNome()
     {
         return name;
     }

}

void main ()
{
     person p = person.fromConsole();

     writeln(p.getNome());
     writeln(p.getIty());
     writeln(p.getHeight());
}


 My goal in learning to use languages like Java, C ++, D is with the
 intention of learning the best way to reuse code and orienation to
 objects and also development cross-platform codes that will run in
 standard ansi for, Unix, Linux, Windows, android etc. ..


Ali
Feb 16 2017
parent Jean Cesar <jeanzonta777 yahoo.com.br> writes:
On Thursday, 16 February 2017 at 22:44:58 UTC, Ali Çehreli wrote:

 On 02/16/2017 02:05 PM, Jean Cesar wrote:


 So I used get methods and sets only as initial pattern to


 netender the

 functioning of the language in relation to some concepts of


 the same

 Makes sense...


 how to leave a very small code with the largest number of
 Possible functionality type


 I think D is very suitable for that.


 I still do not know very well or use
 constructors in C ++


 Understandable: Many coding guidelines eschew doing non-trivial 
 work in constructors. They require a member function like 
 obj.initialize(/* ... */) to be called in order to get a 
 functioning object.


 but I have very high potential in a code with
 multiple inheritance


 That's going to be a problem because D does not allow multiple 
 inheritance.


 I think of compilers in the case of the code that
 favors me in reading so I would do something like:

 void main ()
 {
    minhaclasse c = new minhaclasse(string text);
    minhaclasse d = new minhaclasse(int number);

  write("Enter your name: ")
  c.set();


 So, your minhaclasse is basically ValorLegível (ReadableValue), 
 which would not scale because likely it's also writable and 
 movable, etc. And that explains why you're looking for multiple 
 inheritance. :)

 // NOT valid D (and no, I don't speak Portuguese)
 class MinhaValor : ValorLegível, ValorEscrita, ValorMóvel /*, 
 ... */ {
     // ...
 }


 void main ()
 {
   string txt;
    Int num;
  write("Enter your name: ")
  minhaclasse(text).set();

  write("Enter your age: ")
  minhaclasse(num).set();

   writeln
    (
     "\n\tString:", minhaclasse(text).print() ;,
     "\n\tInt:", minhaclasse(num).print();
    );
 }

 I think of object orientation this way to avoid getting


 rewritten many

 things so I would only define what the set or get would


 return by

 initializing the constructor only but I have no idea how to


 do that ..

 You make it sound as if OOP is for code reuse or for reducing 
 code repetition. I think regular functions provide that already.

 Unless polymorphism is really beneficial, functional style is 
 preferable. Additionally, D has this very useful universal 
 function call syntax (UFCS), which makes your use case easy to 
 implement, and which my earlier code could have benefited from 
 as well.

 import std.stdio;
 import std.traits;

 auto read(T)(ref T t, string message)
 if (!isSomeString!T) {
     writef("%s: ", message);
     readf(" %s", &t);
     return t;
 }

 auto read(S)(ref S s, string message)
 if (isSomeString!S) {
     import std.string : strip;
     writef("%s: ", message);
     s = readln().strip();
     return s;
 }

 class person
 {
 private:
     string name, address;
     int age;
     float height;

 public:
     static person fromConsole()
     {
         auto p = new person();
         /* UFCS in action: Note how these are not written as
          *    read(p.name, /* ... */)
          */
         p.name.read("Enter Your Name");
         p.age.read("Enter Your Age");
         p.height.read("Enter Your Height");
         return p;
     }

     float getHeight()
     {
         return height;
     }

     int getIty()
     {
         return age;
     }

     string getNome()
     {
         return name;
     }

 }

 void main ()
 {
     person p = person.fromConsole();

     writeln(p.getNome());
     writeln(p.getIty());
     writeln(p.getHeight());
 }


 My goal in learning to use languages like Java, C ++, D is


 with the

 intention of learning the best way to reuse code and


 orienation to

 objects and also development cross-platform codes that will


 run in

 standard ansi for, Unix, Linux, Windows, android etc. ..


 Ali


I tried to define a method to read vectors of chars but this is 
giving error

auto read(C)(ref C c, char[] message)
if (!isSomeChar!C) {
     writef("\n\t%s: ", message);
     read(" %s", &c);
     return c;
}
Feb 16 2017