OCA JAVA - 3 Programming with Java Operators
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This document provides an overview of Java operators, including fundamental, assignment, arithmetic, relational, equality, logical, and precedence operators. It explains how these operators function, their usage with different operands, and the concept of operator precedence and associativity in Java. Additionally, it emphasizes the importance of understanding these operators for effective programming in Java.
![Precedence and Associativity
of Java Operators
Operator Description Level Associativity
[] Access array element 1 Left to right
. Access object member
() Invoke a method
++ Post-increment
-- Post-decrement
++ Pre-increment 2 Right to left
-- Pre-decrement
+ Unary plus
- Unary minus
! Logical NOT
~ Bitwise NOT](https://image.slidesharecdn.com/3-programmingwithjavaoperators-150202170137-conversion-gate02/85/OCA-JAVA-3-Programming-with-Java-Operators-16-320.jpg)
OCA JAVA - 3 Programming with Java Operators
- 1. 3. Programming with Java Operators • Understanding Fundamentals Operators • Understanding Operator Precedence By Fernando Gil Date: Jan 2015 Version: 1.0 Based in the book OCA Java SE 7 Programmer I Study Guide (Examn 1Z0-803)
- 2. 1. Understanding Fundamental Operators • Java operators are used to return a result from an expression using one, two, or three operands • Operands are the values placed to the right or left side of the operators • Prefix/postfix – increment/decrement operators use one operand • The conditional ternary operator (?:) uses three operands • All other operators use two operands
- 4. Assignment Operators • Assignment operators are used to assign values to variables • The assignment operator by itself is the equal sign • At it simplest, the assignment operator moves valid literals into variables • Assignment operators cause compiler errors when the literals are not valid for the variable to which they are assigned
- 5. Compound Assignment Operators • Compound assignment operators provide a shorter syntax for assigning the result of an arithmetic or bitwise operator • They perform the operation on the two operands before assigning the result to the first operand • There are 11 compound assignment operators • While the use of compound assignment operators cuts down on keystrokes, it is generally good practice to use the longhand approach since the code is clearly more readable
- 6. Operator Function += Assigns the result of the addition - = Assigns the result of the subtraction *= Assigns the result of the multiplication /= Assigns the result of the division %= Assigns the remainder of the division &= Assigns the result of the logical AND |= Assigns the result of the logical OR ^= Assigns the result of the logical XOR <<= Assigns the result of the signed left bit shift >>= Assigns the result of the signed right bit shift >>>= Assigns the result of the unsigned right bit shift
- 7. Basic Arithmetic Operators Operator Function + Addition (sum) operator - Subtraction (difference) operator * Multiplication (product) operator / Division (quotient) operator % Modulus (remainder) operator int totalCannonBalls = greyCannonBalls + blackCannonBalls;
- 8. Prefix and Postfix Operators Operator Function ++ X Prefix increment operator -- X Prefix decrement operator X++ Postfix increment operator X -- Postfix decrement operator • The execution of prefix operators occurs on the operand prior to the evaluation of the whole expression • The execution of postfix operators occurs after the expression has been evaluated
- 9. Basic Relational Operators Operator Function < Less than operator <= Less than or equal to operator > Greater than operator >= Greater than or equal to operator • Those operators are used to compare integers, floating points, and characters • When the expression used with the relational operators is true, the Boolean value of true is returned; otherwise, false is returned
- 10. Equality Operators Operator Function == Equal to operator != Not equal to operator • Relational operators that directly compare the equality of primitives and object reference variables are considered equality operators
- 11. Logical Operators Operator Function && Logical AND to operator || Logical OR operator • Logical (conditional) operators evaluate a pair of Boolean operands. If both values of the operands have a value of true, then a value of true is returned • To return true with the AND operator both operands would need to be true. • To return true with the OR operator only one operand needs to be true
- 12. Logical Negation Operator Operator Function ! Logical negation operator • It is also known as the inversion operator or Boolean invert operator, and it returns the opposite of a Boolean value • Expect to see the logical negation operator used in conjunction with any method or expression that return a Boolean value • This operator cannot be used on a non-Boolean value
- 13. 2. Understanding Operator Precedence • Operator precedence is the order in which operators will be evaluated when several operators are included in an expression • Operators with a higher precedence are evaluated before operators with a lower precedence • Operator precedence can be overridden using parentheses • When multiple sets of parentheses are present, the innermost set is evaluated first
- 14. Precedence Order • When two operators share an operand, the operator with the higher precedence goes first. For example: 1 + 2 * 3 is treated as 1 + (2 * 3) whereas 1 * 2 + 3 is treated as (1 * 2) + 3 since multiplication has a higher precedence than addition
- 15. Associativity • When an expression has two operators with the same precedence, the expression is evaluated according to its associativity. For example: x = y = z = 17 is treated as x = (y = (z = 17)) leaving all three variables with the value 17, since the = operator has right-to-left associativity. On the other hand, 72 / 2 / 3 is treated as (72 / 2) / 3 since the / operator has left-to-right associativity.
- 16. Precedence and Associativity of Java Operators Operator Description Level Associativity [] Access array element 1 Left to right . Access object member () Invoke a method ++ Post-increment -- Post-decrement ++ Pre-increment 2 Right to left -- Pre-decrement + Unary plus - Unary minus ! Logical NOT ~ Bitwise NOT
- 17. Operator Description Level Associativity () Cast 3 Right to left new Object creation * Multiplicative 4 Left to right / % + - Additive 5 Left to right + String concatenation << >> Shift 6 Left to right >>> < <= Relational type comparison 7 Left to right > >= == Equality 8 Left to right != & Bitwise AND 9 Left to right ^ Bitwise XOR 10 Left to right
- 18. Operator Description Level Associativity | Bitwise OR 11 Left to right && Conditional AND 12 Left to right || Conditional OR 13 Left to right ?: Conditional 14 Right to left = += -= Assignment 15 Right to left *= /= %= &= ^= |= <<= >>= >>>=
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