# Shorthand operators

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```					Shorthand operators
Shorthand operators

• Shorthand operator:
• A shorthand operator is a shorter way to express
something that is already available in the Java
programming language
• Shorthand operations do not add any feature to the
Java programming language
(So it's not a big deal).
Shorthand operators +=, -=, *=, /= and *=

• A frequent construct is the following:

x is a variable in the program

x = x + value ; // Add value to the variable x
x = x - value ; // Subtract value to the variable x
x = x * value ; // Increase the variable x by value times
and so on...

Java has a shorthand operator for these kinds of assignment
statements
Shorthand operators +=, -=, *=, /= and *=
(cont.)
• Operator assignment short hands:

Operator    Name of the      Example    Equivalent
symbol       operator                   construct
+=            Addition        x += 4;   x = x + 4;
assignment
-=            Subtraction     x -= 4;   x = x - 4;
assignment
*=            Multiplicatio   x *= 4;   x = x * 4;
n assignment
/=            Division        x /= 4;   x = x / 4;
assignment
%=            Remainder       x %= 4;   x = x % 4;
assignment
Shorthand operators +=, -=, *=, /= and *=
(cont.)
• Exercise: what is printed by the following program
public class Shorthand1
{
public static void main(String[] args)
{
int x;

x = 7;
x += 4;
System.out.println(x);

x = 7;
x -= 4;
System.out.println(x);
Shorthand operators +=, -=, *=, /= and *=
(cont.)

x = 7;
x *= 4;
System.out.println(x);

x = 7;
x /= 4;
System.out.println(x);

x = 7;
x %= 4;
System.out.println(x);
}
}
Shorthand operators +=, -=, *=, /= and *=
(cont.)
• Example Program: (Demo above code)
– Prog file:
http://mathcs.emory.edu/~cheung/Courses/170/Syllabus/04/Progs/
Shorthand1.java
• How to run the program:

• Right click on link and save in a scratch directory
• To compile: javac Shorthand1.java
• To run:     java Shorthand1 (You will see the
Increment and decrement shorthand
operators
• Two very commonly used assignment statements are:

1. x = x + 1;

and

2. x = x - 1;

x is a variable in the program

• Java has shorthand operators to increment and decrement a
variable by 1 (one).
Increment and decrement shorthand
operators (cont.)
• Increment and decrement operators:

Operator    Name of the    Example    Equivalent
symbol       operator                 construct

++         Increment         x++;   x = x + 1;

--        Decrement         x--;   x = x - 1;
Increment and decrement shorthand
operators (cont.)
• Exercise: what is printed by the following program

public class Shorthand2
{
public static void main(String[] args)
{
int x;

x = 7;
x++;
System.out.println(x);

x = 7;
x--;
System.out.println(x);
}
}
Increment and decrement shorthand
operators (cont.)
• Example Program: (Demo above code)
– Prog file:
http://mathcs.emory.edu/~cheung/Courses/170/Syllabus/04/Progs/
Shorthand2.java
• How to run the program:

• Right click on link and save in a scratch directory
• To compile: javac Shorthand2.java
• To run:     java Shorthand2 (You will see the