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The syntax for declaring a variable is as follows:
<data type> <name of the variable>;
Where, the <data type> specifies any primitive or non-primitive data type and the name of the variable should
be a valid Java identifier. For example, int age; Here, int is the data type and the age is the variable name.
As you know, that every statement is terminated with the help of a semicolon. Similarly, the declaration statement
is also terminated by using a semicolon.
For example:
int age;
Here, int is the data type, and age is the variable name.
You can also declare multiple variables of the same type in a single statement, separating them with commas.
For example:
int age, marks;
4.6.2 Initialise a Variable
Initialisation is the assignment of a value to a variable at the time of declaration with the help of ‘=’ (equal to
operator). Assignment is simply the storing of a value to a variable. The assignment operator assigns the value at
the right side of it to the variable at the left side of it. For example, a = 10; In Java, initial default values are not
assigned to local variables when it is created and before using local variable compiler checks whether it is assigned
or not. You can initialise a variable in the same line that declares it. To do that you should follow this general form,
type name = expression;
For examples:
double d = 4.5;
String n= "India"; (Here we are declaring and assigning the variable in a single statement.)
int a = 5;
char c=‘a’;
Java allows you to declare more than one variable in a one statement, then each variable should have a value of
its own. For example: float i = 45f, j = 12f;
Variables can be initialised in two ways, static initialisation and dynamic initialisation.
Static Initialisation
Assigning values to variables at the time of declaration is called Static Initialisation. At the time of its declaration
the variable is initialised.
Some examples are:
Data types Declaration Static Initialisation
int int a; a = 20;
float float f; f=20.0 f;
double double d; d= 20.0;
char char c; c= ‘a’;
String String s; s= “India”;
boolean boolean b; b= false;
68 Touchpad Computer Applications-IX

