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Which of the following is NOT a component of arithmetic expressions?
Which of the following is NOT a component of arithmetic expressions?
Unary operators operate on two operands.
Unary operators operate on two operands.
False
What purpose do assignment statements serve in imperative programming languages?
What purpose do assignment statements serve in imperative programming languages?
They specify computations by assigning values to variables.
The operator precedence rules dictate the order in which adjacent operators are evaluated, with parentheses having the highest precedence, followed by unary operators, then ____, ____, and finally ____.
The operator precedence rules dictate the order in which adjacent operators are evaluated, with parentheses having the highest precedence, followed by unary operators, then ____, ____, and finally ____.
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Match the following types of operators with their definitions:
Match the following types of operators with their definitions:
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Which design issue relates to how operators are grouped in an expression?
Which design issue relates to how operators are grouped in an expression?
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In arithmetic expressions, parentheses always have the lowest precedence.
In arithmetic expressions, parentheses always have the lowest precedence.
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Identify one of the motivations for developing the first programming languages related to arithmetic.
Identify one of the motivations for developing the first programming languages related to arithmetic.
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Which operator is evaluated from right to left?
Which operator is evaluated from right to left?
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All operators in APL have different precedence levels.
All operators in APL have different precedence levels.
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What is the purpose of parentheses in expressions?
What is the purpose of parentheses in expressions?
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In C-based languages, a conditional expression typically uses the ______ operator.
In C-based languages, a conditional expression typically uses the ______ operator.
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What is the first step in operand evaluation order?
What is the first step in operand evaluation order?
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Functional side effects can cause unintended changes in an expression.
Functional side effects can cause unintended changes in an expression.
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Name one disadvantage of disallowing functional side effects in programming languages.
Name one disadvantage of disallowing functional side effects in programming languages.
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Match the programming concept with its description:
Match the programming concept with its description:
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Which of the following operators is NOT a Boolean operator in C?
Which of the following operators is NOT a Boolean operator in C?
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In C, Boolean expressions are evaluated using the boolean type.
In C, Boolean expressions are evaluated using the boolean type.
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What is the purpose of short-circuit evaluation?
What is the purpose of short-circuit evaluation?
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In the expression 'a < b < c', C evaluates the first part and compares it to ______.
In the expression 'a < b < c', C evaluates the first part and compares it to ______.
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Match the following Boolean operators to their languages:
Match the following Boolean operators to their languages:
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What does the unary operator '!' do in C?
What does the unary operator '!' do in C?
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Short-circuit evaluation is used in all Boolean expressions in C.
Short-circuit evaluation is used in all Boolean expressions in C.
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Explain the characteristic of C's expression 'a < b < c'.
Explain the characteristic of C's expression 'a < b < c'.
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What is operator overloading?
What is operator overloading?
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A narrowing conversion can convert a float to an int without losing information.
A narrowing conversion can convert a float to an int without losing information.
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What is a coercion in mixed-mode expressions?
What is a coercion in mixed-mode expressions?
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In C, explicit type conversion is commonly called ______.
In C, explicit type conversion is commonly called ______.
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Which of the following is a potential problem with user-defined overloaded operators?
Which of the following is a potential problem with user-defined overloaded operators?
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Widening conversions may always cause loss of precision.
Widening conversions may always cause loss of precision.
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Match the following conversion types with their definitions:
Match the following conversion types with their definitions:
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A mixed-mode expression consists of operands of ______ types.
A mixed-mode expression consists of operands of ______ types.
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Which assignment operator is used in FORTRAN and Java?
Which assignment operator is used in FORTRAN and Java?
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In C-based languages, the result of an assignment statement cannot be used as an operand.
In C-based languages, the result of an assignment statement cannot be used as an operand.
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What does the compound assignment operator 'a += b' signify?
What does the compound assignment operator 'a += b' signify?
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In Pascal, integer variables can be assigned to real variables, but real variables cannot be assigned to ________.
In Pascal, integer variables can be assigned to real variables, but real variables cannot be assigned to ________.
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What is the equivalent of the conditional target '(flag) ? total : subtotal = 0'?
What is the equivalent of the conditional target '(flag) ? total : subtotal = 0'?
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Unary assignment operators like 'count++' are only used for incrementing operations.
Unary assignment operators like 'count++' are only used for incrementing operations.
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The operator '+' can be used in assignment statements for both addition and ________.
The operator '+' can be used in assignment statements for both addition and ________.
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Match the programming language with its assignment behavior:
Match the programming language with its assignment behavior:
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Study Notes
Chapter 6: Expressions and Assignment Statements
- Programming languages use expressions to specify computations.
- Understanding expression evaluation requires familiarity with operator and operand evaluation rules.
- Imperative languages heavily rely on assignment statements.
Chapter 5 Topics
- Programming languages use arithmetic expressions and assignment statements.
- Arithmetic expressions consist of operators, operands, parentheses, and function calls.
Introduction
- Expressions are fundamental for specifying computations in programming languages.
- Proper expression evaluation relies on understanding operator and operand precedence and evaluation order.
- Assignment statements are vital to imperative programming, with the assignment operator playing a central role.
Arithmetic Expressions
- Arithmetic evaluation was a key motivator for developing programming languages.
- Arithmetic expressions use operators, operands, parentheses, and function calls.
Arithmetic Expressions: Design Issues
- Operator precedence rules dictate the order of operations.
- Operator associativity rules dictate the order of operations when operators have the same precedence.
- Operand evaluation order impacts side effects.
- Operator overloading and mixed-mode expressions also pose challenges.
Arithmetic Expressions: Operators
- Unary operators have one operand.
- Binary operators have two operands.
- Ternary operators have three operands.
Arithmetic Expressions: Operator Precedence Rules
- Operators with higher precedence are evaluated first.
- Parenthesis override precedence rules.
- Unary operators (e.g., +, -) have higher precedence.
- Multiplication and division have higher precedence than addition and subtraction.
Arithmetic Expressions: Operator Associativity Rules
- Operators with the same precedence are evaluated according to their associativity (typically left-to-right).
- Exponentiation (**) is a notable exception; it typically associates right-to-left.
- Associativity rules can be overridden using parentheses.
Arithmetic Expressions: Conditional Expressions
- Conditional expressions (e.g., those with a ternary operator) are evaluated based on conditional statements.
- Expressions in C-based languages are evaluated sequentially and the value of the left operands determines the next expression.
Arithmetic Expressions: Operand Evaluation Order
- Variable values are fetched from memory.
- Constants are often already part of the machine instruction.
- Expressions within parentheses are evaluated first.
Arithmetic Expressions: Potentials for Side Effects
- Functional side effects occur when a function modifies a variable outside its scope.
- Side effects in expressions can lead to unpredictable behavior.
Functional Side Effects
- The language must be designed to avoid side effects in functions.
- Two solutions are to define away side effects or mandate a specific fixed operand evaluation order.
Overloaded Operators
- Operators can be overloaded to perform different operations based on operand types.
- Operator overloading in C/C++ can lead to loss of compiler error detection or readability issues.
- New symbols can avoid problems with operator overloading.
Overloaded Operators (continued)
- C++ and Ada support user-defined overloaded operators, but this brings potential problems in terms of unexpected operations or confusing readability.
Type Conversions
- Narrowing conversions can lead to data loss, converting from float or double to int.
- Widening conversions, when possible, can convert to a larger type without data loss.
Type Conversions: Mixed Mode
- Mixed-mode expressions involve operands of different types.
- Type coercions occur implicitly.
- Implicit coercions decrease a compiler's ability to detect type errors.
Explicit Type Conversions
- Explicit type conversions, often called casting, are commonly supported in C-family languages.
- Specific syntax varies among languages (such as using parenthesis to specify the target type).
Type Conversions: Errors in Expressions
- Arithmetic operations have inherent limitations like division by zero or overflow/underflow.
- Run-time systems often ignore or handle these errors differently, leading to unexpected behavior.
Relational and Boolean Expressions
- Relational expressions use operators and operands to compare values.
- Boolean expressions result in either true or false values.
- Operator symbols for relational operators can vary across languages.
Relational and Boolean Expressions: No Boolean Type in C
- C uses integers (0 for false, non-zero for true) rather than a dedicated Boolean type.
- Evaluating expressions like a < b < c yields results that may not be intuitive due to operator precedence and evaluation from left to right.
Relational and Boolean Expressions: Operator Precedence
- Operator precedence determines the order of operations in relational and Boolean expressions in C-family languages.
Short Circuit Evaluation
- Short-circuit evaluation strategies evaluate operands only when necessary to avoid potential errors/problems.
- Some languages use short-circuit evaluation for Boolean operators like && and ||.
Short Circuit Evaluation (continued)
- Some languages (like Ada) let programmers choose between short-circuit and non-short-circuit evaluation for Boolean operators.
Assignment Statements
- Assignment statements use the assignment operator to store a value in a variable.
- Different languages have different symbols for the assignment operator.
Assignment Statements: Conditional Targets
- Conditional targets in C-style languages enable conditional assignments (using a conditional expression).
Assignment Statements: Compound Assignment Operators
- Compound assignment operators are a shorthand for typical assignment operations (e.g., a += b is equivalent to a = a + b).
Assignment Statements: Unary Assignment Operators
- Unary operators in C++ and C combine with assignment.
Assignment as an Expression
- Assignment statements in C/C++ generate a result.
- The result of the assignment can be used in other expressions.
Mixed-Mode Assignment
- Mixed-mode assignment involves assigning values of different types to a variable.
- Language-specific rules govern how type conversions handle such cases.
Summary
- Expressions use precedence and associativity rules, including operator overloading and mixed-operator assignments.
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Description
Test your knowledge on arithmetic expressions used in programming languages. This quiz covers operator precedence, assignment statements, and the structure of arithmetic expressions. Brush up on your understanding of how various operators function in imperative programming languages.
