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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;

Dynamic Initialisation

Assigning values to variables during runtime, often based on some logic or user input called dynamic
initialisation. Some examples are:

Data types Declaration Dynamic Initialisation
int int a1, a2, a3; a1=a2 + a3;

float float i1,i2,i3; i1=i2 + i3;
String String c= “India”, d= “Delhi” e= c + d;
, e;

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