how to declare variable in android

1I suggest learning Java fundamentals first. Declaring a variable is fundamental to Java programming language (and indeed many programming languages), its not just Android specific.
2
3You can learn Java fundamentals here.
4
5Good Luck in your learning

1var1 = 'variable1';
2var2 = 'variable2';

1public class MyApplication extends Application {
2
3    private String someVariable;
4
5    public String getSomeVariable() {
6        return someVariable;
7    }
8
9    public void setSomeVariable(String someVariable) {
10        this.someVariable = someVariable;
11    }
12}