Page 106 - computer science (868) class 11
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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
we can use an underscore (_) to separate the words.
For example:
int a = 5; double sum_of_numbers = 40.5;
5.1.2 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. They may be positive, negative or zero. For
example, 78, +456, -765, etc.
• Floating-point Literals: Floating-point Literals are the fractional 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 a set of characters that are enclosed in double quotations. For
example, “India”, “Kolkata 700115”, “I am an Indian”, etc.
• Boolean Literals: Boolean Literals contain two values only: 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’.
5.1.3 Assignment
Assigning a value to a variable using the symbol “=” is known as an assignment. This “=” is an assignment operator. The
default value is ‘no 11’.
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. Actually, as soon as a variable
is declared, it contains a garbage values. This garbage value has to be removed, as it may lead us to a wrong result.
• Static Initialisation: When a constant is directly assigned to a variable, it is known as Static Initialisation. For example,
int a=6;
String n="Name";
• Dynamic Initialisation: When a variable is initialised during the execution/run time 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);
104104 Touchpad Computer Science-XI

