B4J Question Simple Console IO in B4J?

[chikega]

I'm having trouble finding an example of a simple input/output Console example in the tutorial documentation. I've found bits and pieces like reading from a text file. But, essentially, how would one translate this Java example (see pic) to B4J? Thank you.

 

[stevel05]

I hadn't tried it before but this is (part) of that code converted.

    Dim System As JavaObject
    System.InitializeStatic("java.lang.System")

    Dim Input As JavaObject
    Input.InitializeNewInstance("java.util.Scanner",Array(System.GetField("in")))
   
    Log("Hello from IDEA!")
    Log("What is your name? ")
    Dim fName As String = Input.RunMethod("nextLine",Null)
    Log("Your Name is " & fName)
    Log("How old are you?")
    Dim Age As Int = Input.RunMethod("nextLine",Null)
    Log("You are " & Age & " years old")

It works, but you will need to run the jar file from the command line and I guess only with java 8.

 

[aeric]

Non-UI Applications

B4J currently supports two types of applications: UI applications (based on JavaFX) and Non-UI applications. Non-UI applications are standard Java applications. Usually the input to such applications is with command line arguments. You should create a new project and select: The program...

www.b4x.com

You can use Log to print text and ReadLine to read input.

 

[stevel05]

ReadLine from which library?

 

[aeric]

ReadLine from which library?

Erel's code is similar to yours. Using JavaObject.

 

[stevel05]

OK, I should have followed the link

 

[aeric]

OK, I should have followed the link

I am sorry I didn't write clearly.

 

[aeric]

Sub Process_Globals
    Private reader As TextReader
End Sub

Sub AppStart (Args() As String)
    Dim sys As JavaObject
    sys.InitializeStatic("java.lang.System")
    reader.Initialize(sys.GetField("in"))
    
    Log("Hello from B4J!")   
    Log("What is your name?")
    Dim fName As String = ReadLine   
    Log($"Your name is ${fName}!"$)
    Log("How old are you?")
    Dim age As Int = ReadLine
    Log($"You are ${age} years old."$)
    Log("What is your GPA?")
    Dim gpa As Double = ReadLine
    Log($"And your GPA of ${gpa} is really good!"$)   
End Sub

Sub ReadLine As String
    Return reader.ReadLine
End Sub

Depends on JavaObject library and run in Release mode with Windows CMD.
For e.g.

java -jar simpleio.jar

 

[chikega]

Thank you Steve and Aeric, I bought you both 'coffees'! ??

 

[aeric]

Thank you Steve and Aeric, I bought you both 'coffees'! ??

Thanks for the gift ?.

 

[stevel05]

Thank you Steve and Aeric, I bought you both 'coffees'! ??

Very kind, thank you

 

[chikega]

Thanks for the gift ?.

Hi Aeric,
Is there a way of printing to console without a CRLF (carriage return and line feed) in B4J?? Essentially the equivalent of Java:

System.out.print();

or C#/VB.Net:

Console.Write();

Thanks! ?

 

[MicroDrie]

The forum rule is a new question is a new thread so that others can find your question and the answer on it.
Without further explanation what you want to achieve exactly, I give a possible solution with [B4X] Smart String Literal

public Sub demo
    Dim Var1 As String = "first"
    Dim Var2 As String = "second"
    Log($"The content is ${Var1} and ${Var2}"$)
End Sub

 

[chikega]

The forum rule is a new question is a new thread so that others can find your question and the answer on it.
Without further explanation what you want to achieve exactly, I give a possible solution with [B4X] Smart String Literal

public Sub demo
    Dim Var1 As String = "first"
    Dim Var2 As String = "second"
    Log($"The content is ${Var1} and ${Var2}"$)
End Sub

Thank you MicroDrie, smart string literal appears to be string interpolation which is cool, but not what I'm looking for. I'm simply looking for the ability to print to a console without a newline. I'll create a new thread.