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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
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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).
Shorthand operators +=, -=, *=, /= and *= • A frequent construct is the following: Java has a shorthand operator for these kinds of assignment statements 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...
Shorthand operators +=, -=, *=, /= and *= (cont.) • Operator assignment short hands:
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 answers on the terminal)
Increment and decrement shorthand operators • Two very commonly used assignment statements are: • Java has shorthand operators to increment and decrement a variable by 1 (one). 1. x = x + 1; and 2. x = x - 1; x is a variable in the program
Increment and decrement shorthand operators (cont.) • Increment and decrement operators:
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 answers on the terminal)