Relational Operators
❑ Relational operators always result in a boolean value (true or false).
❑ There are six relational operators: >, >=, <, <=, ==, and !=. The last two (== and !=) are sometimes referred to as equality operators.
❑ When comparing characters, Java uses the Unicode value of the character as the numerical value.
❑ Equality operators
❑ There are two equality operators: == and !=.
❑ Four types of things can be tested: numbers, characters, booleans, and reference variables.
❑ When comparing reference variables, == returns true only if both references refer to the same object.
instanceof Operator
❑ instanceof is for reference variables only, and checks for whether the object is of a particular type.
❑ The instanceof operator can be used only to test objects (or null) against class types that are in the same class hierarchy.
❑ For interfaces, an object passes the instanceof test if any of its superclasses implement the interface on the right side of the instanceof operator.
Arithmetic Operators
❑ There are four primary math operators: add, subtract, multiply, and divide.
❑ The remainder operator (%), returns the remainder of a division.
❑ Expressions are evaluated from left to right, unless you add parentheses, or unless some operators in the expression have higher precedence than others.
❑ The *, /, and % operators have higher precedence than + and -.
String Concatenation Operator
❑ If either operand is a String, the + operator concatenates the operands.
❑ If both operands are numeric, the + operator adds the operands.
Increment/Decrement Operators
❑ Prefix operators (++ and --) run before the value is used in the expression.
❑ Postfix operators (++ and --) run after the value is used in the expression.
❑ In any expression, both operands are fully evaluated before the operator is applied.
❑ Variables marked final cannot be incremented or decremented.
Ternary (Conditional Operator)
❑ Returns one of two values based on whether a boolean expression is true or false.
❑ Returns the value after the ? if the expression is true.
❑ Returns the value after the : if the expression is false.
Logical Operators
❑ The exam covers six "logical" operators: &, |, ^, !, &&, and ||.
❑ Logical operators work with two expressions (except for !) that must resolve to boolean values.
❑ The && and & operators return true only if both operands are true.
❑ The || and | operators return true if either or both operands are true.
❑ The && and || operators are known as short-circuit operators.
❑ The && operator does not evaluate the right operand if the left operand is false.
❑ The || does not evaluate the right operand if the left operand is true.
❑ The & and | operators always evaluate both operands.
❑ The ^ operator (called the "logical XOR"), returns true if exactly one operand is true.
❑ The ! operator (called the "inversion" operator), returns the opposite value of the boolean operand it precedes.
❑ Relational operators always result in a boolean value (true or false).
❑ There are six relational operators: >, >=, <, <=, ==, and !=. The last two (== and !=) are sometimes referred to as equality operators.
❑ When comparing characters, Java uses the Unicode value of the character as the numerical value.
❑ Equality operators
❑ There are two equality operators: == and !=.
❑ Four types of things can be tested: numbers, characters, booleans, and reference variables.
❑ When comparing reference variables, == returns true only if both references refer to the same object.
instanceof Operator
❑ instanceof is for reference variables only, and checks for whether the object is of a particular type.
❑ The instanceof operator can be used only to test objects (or null) against class types that are in the same class hierarchy.
❑ For interfaces, an object passes the instanceof test if any of its superclasses implement the interface on the right side of the instanceof operator.
Arithmetic Operators
❑ There are four primary math operators: add, subtract, multiply, and divide.
❑ The remainder operator (%), returns the remainder of a division.
❑ Expressions are evaluated from left to right, unless you add parentheses, or unless some operators in the expression have higher precedence than others.
❑ The *, /, and % operators have higher precedence than + and -.
String Concatenation Operator
❑ If either operand is a String, the + operator concatenates the operands.
❑ If both operands are numeric, the + operator adds the operands.
Increment/Decrement Operators
❑ Prefix operators (++ and --) run before the value is used in the expression.
❑ Postfix operators (++ and --) run after the value is used in the expression.
❑ In any expression, both operands are fully evaluated before the operator is applied.
❑ Variables marked final cannot be incremented or decremented.
Ternary (Conditional Operator)
❑ Returns one of two values based on whether a boolean expression is true or false.
❑ Returns the value after the ? if the expression is true.
❑ Returns the value after the : if the expression is false.
Logical Operators
❑ The exam covers six "logical" operators: &, |, ^, !, &&, and ||.
❑ Logical operators work with two expressions (except for !) that must resolve to boolean values.
❑ The && and & operators return true only if both operands are true.
❑ The || and | operators return true if either or both operands are true.
❑ The && and || operators are known as short-circuit operators.
❑ The && operator does not evaluate the right operand if the left operand is false.
❑ The || does not evaluate the right operand if the left operand is true.
❑ The & and | operators always evaluate both operands.
❑ The ^ operator (called the "logical XOR"), returns true if exactly one operand is true.
❑ The ! operator (called the "inversion" operator), returns the opposite value of the boolean operand it precedes.
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