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Earlier modules have touched briefly on the topic of operators. This module discusses Java operators in depth.

Revised: Mon Mar 28 13:56:51 CDT 2016

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Table of contents

Preface

Earlier modules have touched briefly on the topic of operators . This module discusses Java operators in depth.

Viewing tip

I recommend that you open another copy of this module in a separate browser window and use the following links to easily find and view the listings while you are reading about them.

Listings

  • Listing 1 . Illustration of prefix and postfix notation.
  • Listing 2 . Illustration of relational operators.

Introduction

The first step in learning to use a new programming language is usually to learn the foundation concepts such as

  • variables,
  • operators,
  • types,
  • expressions,
  • flow-of-control, etc.

This module concentrates on the operators used in Java.

Operators

Unary and binary operators

Java provides a set of operators that can be used to perform an action on one, two, or three operands. An operator that operates on one operand is called a unary operator. An operator that operates on two operands is called a binary operator. An operator that operates on three operands is called a ternary operator.

Some operators can behave either as a unary or as a binary operator. The best known such operator is probably the minus sign (-) . As a binary operator, the minus sign causes its right operand to be subtracted from its left operand. As a unaryoperator, the minus sign causes the algebraic sign of the right operand to be changed.

A ternary operator

Java has only one operator that takes three operands. It is a conditional operator, which I sometimes refer to as a cheap if statement.

The first operand is a boolean expression, which is followed by a questionmark character (?) . The question mark is followed by a second operand, which is followed by a colon character (:) . The colon character is followed by the third operand.

If the boolean expression evaluates to true, the value of the operand following the ? is returned. Otherwise, the value of the operand following the : is returned.

An example of the syntax follows:

Ternary operator syntax

boolean expression ? value1 : value2

Overloaded operators

Unlike C++, Java does not support the creation of overloaded operators in program code. (If you don't know what this means, don't worry about it.)

Operators from previous programs

The statements in the following note box illustrate the use of the following operators from Java programs in earlier modules :

  • =
  • !=
  • +
  • (char)
Operators from previous programs int ch1, ch2 = '0'; while( (ch1 = System.in.read() ) != '#') ch2 = ch1;System.out.println("The char before the # was " + (char)ch2);

The plus and cast operators

Of particular interest in this list is the plus sign (+) and the cast operator (char) .

Questions & Answers

A golfer on a fairway is 70 m away from the green, which sits below the level of the fairway by 20 m. If the golfer hits the ball at an angle of 40° with an initial speed of 20 m/s, how close to the green does she come?
Aislinn Reply
cm
tijani
what is titration
John Reply
what is physics
Siyaka Reply
A mouse of mass 200 g falls 100 m down a vertical mine shaft and lands at the bottom with a speed of 8.0 m/s. During its fall, how much work is done on the mouse by air resistance
Jude Reply
Can you compute that for me. Ty
Jude
what is the dimension formula of energy?
David Reply
what is viscosity?
David
what is inorganic
emma Reply
what is chemistry
Youesf Reply
what is inorganic
emma
Chemistry is a branch of science that deals with the study of matter,it composition,it structure and the changes it undergoes
Adjei
please, I'm a physics student and I need help in physics
Adjanou
chemistry could also be understood like the sexual attraction/repulsion of the male and female elements. the reaction varies depending on the energy differences of each given gender. + masculine -female.
Pedro
A ball is thrown straight up.it passes a 2.0m high window 7.50 m off the ground on it path up and takes 1.30 s to go past the window.what was the ball initial velocity
Krampah Reply
2. A sled plus passenger with total mass 50 kg is pulled 20 m across the snow (0.20) at constant velocity by a force directed 25° above the horizontal. Calculate (a) the work of the applied force, (b) the work of friction, and (c) the total work.
Sahid Reply
you have been hired as an espert witness in a court case involving an automobile accident. the accident involved car A of mass 1500kg which crashed into stationary car B of mass 1100kg. the driver of car A applied his brakes 15 m before he skidded and crashed into car B. after the collision, car A s
Samuel Reply
can someone explain to me, an ignorant high school student, why the trend of the graph doesn't follow the fact that the higher frequency a sound wave is, the more power it is, hence, making me think the phons output would follow this general trend?
Joseph Reply
Nevermind i just realied that the graph is the phons output for a person with normal hearing and not just the phons output of the sound waves power, I should read the entire thing next time
Joseph
Follow up question, does anyone know where I can find a graph that accuretly depicts the actual relative "power" output of sound over its frequency instead of just humans hearing
Joseph
"Generation of electrical energy from sound energy | IEEE Conference Publication | IEEE Xplore" ***ieeexplore.ieee.org/document/7150687?reload=true
Ryan
what's motion
Maurice Reply
what are the types of wave
Maurice
answer
Magreth
progressive wave
Magreth
hello friend how are you
Muhammad Reply
fine, how about you?
Mohammed
hi
Mujahid
A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of 500.00 N applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the 3.00 m of the string?
yasuo Reply
Who can show me the full solution in this problem?
Reofrir Reply
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Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
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