Page 137 - ComputerScience_Class_11

We know that a variable is a named memory location where a value is being stored. The name of the variable contains
any combination of letters without any space.
But we should remember that it must not start with any digit. If the name is a combination of two or more words, then
Primitive valueS, wraPPer we can use an underscore (_) to separate the words.
For example:
claSSeS, tyPeS aNd caStiNg
int a = 5; double sum_of_numbers = 40.5;
6.1.2 Literals
The values that are stored in the variables are known as literals. These values can be of any data type.

int a = 10;
double d = 11.55;
String s = "India is a country";
Types of Literals
There are six different types of literals. They are integer literals, floating-point literals, character literals, string literals,
boolean literals and null literals. Let us learn about them in detail.
• Integer literals: Integer literals are the whole numbers of any length, without any fractional part. They may be
positive, negative or zero. For example, 78, +456, -765, etc.
• Floating-point literals: Floating-point literals are the fractional or real numbers. They are also called real literals.
They may be positive or negative. For example, 2.65, 985.94, -5.68, etc.
• Character literals: Character literals are the alphabets, numbers or symbols enclosed in single quotes. For example,
‘B’, ‘^’, ‘5’, etc.
• String literals: String literals are a sequence of characters that are enclosed in double quotations. For example,
“India”, “Kolkata 700115”, “I am an Indian”, etc.
• Boolean literals: Boolean literals represent logical values. They can have only two values: true or false.
• Null literals: Null literals represent the null value in a string variable when we need to initialise it. The default value
is ‘null’.

6.1.3 Assignment
Assigning a value to a variable using the symbol “=” is known as an assignment. This “=” is an assignment operator.
int a = 5; // here 5 is assigned to the variable a
double b = 6.7; // here 6.7 is assigned to the variable b
Initialisation
Initialisation is the assignment of a value to a variable at the time of declaration.

Types of Initialisation
There are two types of initialisations. They are static initialisation and dynamic initialisation. As soon as a variable is
declared, it contains garbage values. This garbage value has to be removed, as it may lead us to a wrong result.
• Static initialisation: When a value is directly assigned to a variable at the time of declaration, it is known as static
initialisation. For example,

int a=6;
String n="Name";
• Dynamic initialisation: When a variable is initialised during the runtime of the program, it is known as dynamic
initialisation. For example,
int a=5, b=6, c; // Known as Static Initialisation
c=a+b; // Known as Dynamic Initialisation
System.out.println(c);

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