-1

Is there any way of calling sequential variable name in java in a for loop like matlab? For example I have variable names like c11,c12,c13... Is there any way i can call them in a for loop as they have c in common and after that the name parts are sequential?

Yu Hao
  • 119,891
  • 44
  • 235
  • 294
Shahreen Shahjahan
  • 1
  • 1
  • 1
    That's not the way to do it... Put the elements in a list and iterate them. – Nir Alfasi May 24 '15 at 16:10
  • 4
    That's what arrays or lists are made for. – runDOSrun May 24 '15 at 16:11
  • Do you want maybe a dictionary-like data structure, such as HashMap? – nbro May 24 '15 at 16:20
  • Possible duplicate: http://stackoverflow.com/questions/17095628/loop-over-all-fields-in-a-java-class. – diogo May 24 '15 at 16:21
  • For this reason you should use Array or ArrayList whichever is compatible or useful according to your need. Just Assign an Array with some variable name let's call **c** and then iterate in the loop with **c[position]**. This will work as like what you are dealing with. – Suraj Palwe May 24 '15 at 16:39
  • Thanks a lot..for the response. But i need to take input from 81 JtextFields which are named like these. Thats why ineeded that. Thanks a lot for your response. – Shahreen Shahjahan May 24 '15 at 17:47
  • 1
    Why are the JTextFields named like that? These fields could also be in an array. – Kasper van den Berg May 24 '15 at 20:04

1 Answers1

0

You can use reflection (see Class.getDeclaredField(String):

MyTextFieldContainer container; // the object that contains the 81 JTextFields

Class<MyTextFieldContainer> containerType = container.getClass();

for (int 1 = 1; i <= 81; i++) {
    string fieldName = "textfield" + i.toString();
    Field fieldReflection = containerType.getDeclaredField(fieldName);
    Object fieldValue = fieldReflection.get(container);
    JTextField textfield = (JTextField)fieldValue;

    … // Use the JTextField however you like
}

Check the various method in Class<T> to select the one that fits your needs:

  • getDeclared…() vs. get…():
    • getDeclared…() returns and field/method/etc. that is declared in containerType (i.e. public, protected, and private), it does not return any inherited fields/methods/etc.;
    • get…() only retrieves public fields/methods/etc. both those declared in containerType and those inherited from base classes and interfaces.
  • get…Field(), get…Method(), and get…Constructor(): return respectively fields, methods, and constructors.
  • get…s() vs. get…(String): getFields() and similar methods return an array of all fields (or methods or contructors) in the class; and getField(String) returns the named field, if it exists.
Kasper van den Berg
  • 8,951
  • 4
  • 48
  • 70
  • I do not recomment this method of accessing the JTextFields, but if you have to you can do it. It's better to redesign your class that contains the 81 JTextFields. – Kasper van den Berg May 24 '15 at 20:29