Page 107 - computer science (868) class 11
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Rules for Naming a Variable
While naming a variable, we need to follow certain rules. They are as follows:
• A variable name should start with a letter.
• A variable name may contain any number of letters, digits and underscores.
• The name should have a meaning related to the program.
• There should not be any space between the letters in the name of the variable.
• Variable names cannot be reserved words.
5.1.4 Punctuators
These are punctuation signs and are used in Java as special characters. Some of them are:
• Semicolon (;) is used for the termination of a statement. For example,
int a=5;
• Dot operator(.) is used to access the scope of a function. For example,
System.out.println() or import java.util.*;
5.1.5 Separators
They are the special characters in Java, which are used to separate the variable or the character. For example,
• Braces () are used to set the priority of a calculation by enclosing any part of an arithmetic, logical, or relational
expression.
• Curly brackets {} are used to enclose compound statements.
• Square brackets [] are used in arrays.
5.1.6 Operators
Operators are the special symbols that signify the compiler to perform some specific mathematical or non-mathematical
operations on one or more operands. Java supports eight types of operators which are as follows:
• Arithmetic Operators: “+”, “-”, “*”, “/”
• Assignment Operators: “=”
• Logical Operators: “&&”, “||”, “!”
• Relational Operators: “==”, “<”, “>”, “<=”, “>=”, “!=”
• Unary Operators: “+”, “-”, “++”, “- -”
• Bitwise Operators: “&”, “|”, “^”, “~”
• Ternary Operators: “?” and “:”
• Shift Operators: (>>), (>>>), (<<), (<<<)
5.2 ESCAPE SEQUENCE
An escape sequence is a non-graphical character preceded by a backslash (\) having a special meaning for the
compiler. It is a command from the keyboard. Some of the escape sequences used in Java are as follows:
Escape Sequence Required for
\t Inserts a horizontal tab.
\b Inserts a backspace.
\n Inserts a new line.
\r Inserts a carriage return.
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Primitive Values, Wrapper Classes, Types and Casting 105

