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Shorthand operators

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• 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).

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• 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

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  • Operator assignment shorthands:

    Operator symbol	Name of the operator	Example	Equivalent construct
    +=	Addition assignment	x += 4;	x = x + 4;
    -=	Subtraction assignment	x -= 4;	x = x - 4;
    *=	Multiplication assignment	x *= 4;	x = x * 4;
    /=	Division assignment	x /= 4;	x = x / 4;
    %=	Remainder assignment	x %= 4;	x = x % 4;

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  • 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); x = 7; x *= 4; System.out.println(x); x = 7; x /= 4; System.out.println(x); x = 7; x %= 4; System.out.println(x); } }

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  • Example Program: (Demo above code)                                                
    • Prog file: click here

    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 answers on the terminal)

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• 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).

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  • Increment and decrement operators:

    Operator symbol	Name of the operator	Example	Equivalent construct
    ++	Increment	x++;	x = x + 1;
    --	Decrement	x--;	x = x - 1;

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  • 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); } }

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  • Example Program: (Demo above code)                                                
    • Prog file: click here

    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 answers on the terminal)