how to hold the previous value used in android

You can make a global class which can have "Getters" and "Setters" to Get and Set a String by extending the Application class.

Read Section 2. By Extending the Application class
http://androidresearch.wordpress.com/2012/03/22/defining-global-variables-in-android/


You can also pass a Bundle to an Activity, which is a method to pass variables between Activities.
http://miragemiko.wordpress.com/2010/03/20/android-using-bundle-for-sharing-variables/

my question if i want to hold the same string value  for the next session how i can do that.

for example

"Let say i had a text and a button. i passed some value and pressed the click button it gave me some output, now i need to hold that immediate previous value to do some other operation or validation, let me know how to do that"

you can, write it to a file
or write to xml
or write to database

then retrieve it when you need it

or if its just from a function, make the function return something

here is psudocide



int x = 5
int y =  functionbla (x)

[now you have two values!! YAY]

roy_sanu,

Before you change the value, you need to put the current value in a String variable. This could be at the top of your click event before the text is changed. Be careful of the scope of the String variable. In other words if you declare it in the click event, then its scope is only in the click event. If you declare it as a Class variable, then it is global to the Class.

Assuming the text box has the value that you want to save and it's an EditText named editText1:

//Find the textbox
EditText etxt = (EditText) this.findViewById(R.id.editText1);                   
//Save the current text value in currentValue
String currentValue = etxt.getText().toString();

Holding the previous session using preferences of android  is the  best  solution