Understanding Unary and Compound Operators in Java
This tutorial provides a comprehensive overview of unary increment, postfix increment, and modulus operations in Java, along with compound operators that modify variable values in place. It highlights the concepts of implicit narrowing conversion and the rules governing type conversions between byte, short, int, char, and long. The examples illustrate how to perform operations and check for even or odd numbers, while emphasizing the requirement of explicit casting in narrowing conversions. Master these fundamental concepts to enhance your Java programming skills.
Understanding Unary and Compound Operators in Java
E N D
Presentation Transcript
연산자 unary increment prefix: ++x; int x = 5; int y = ++x; System.out.print( x + “, “ + y); unary increment postfix: x++; int x = 5; int y = x++; System.out.print( x + “, “ + y); Output Output File Edit WindowHelp File Edit WindowHelp 6, 6 6, 5
modulus - % int x = 5 % 3; System.out.print(x); Output File Edit WindowHelp 2
modulus - % 짝수? 홀수? if(x % 2 == 0)… 짝수 else…홀수
Compound Operators • x += 5; • x -= 5; • x *= 5; • x /= 5; • x %= 5; int x = 10; • x = x + 5; • x = x – 5; • x = x * 5; • x = x / 5; • x = x % 5; • 15 • 5 • 50 • 2 • 0
Implicit Narrowing Conversion byte b = 2; b = b + 10; byte b = 2; b +=10;
무슨 conversion? • short > int • byte > long • float > long • char > int • char > short • byte > char
무슨 conversion? • short > int • byte > long • float > long • char > int • char > short • byte > char • widening • widening • narrowing • widening • narrowing • narrowing
conversions byte short int long char
conversions between byte, short and char are ALWAYS narrowing conversions requiring explicit cast byte short int long char
conversions between byte, short and char are ALWAYS narrowing conversions requiring explicit cast byte short char Narrowing Conversion
conversions between byte, short and char are ALWAYS narrowing conversions requiring explicit cast byte char short Narrowing Conversion
conversions between byte, short and char are ALWAYS narrowing conversions requiring explicit cast byte b = 16; char c = No! b;
conversions between byte, short and char are ALWAYS narrowing conversions requiring explicit cast byte b = 16; char c = b; (char)
65535 127 byte -128 char 0
