Concepts Of Programming Language Final

Front 1

During the evaluation of a function, the value of the parameter

Back 1

cannot change throughout the evaluation

Front 2

A scheme lambda function that returns the cube of its first argument less the square of its second would be

Back 2

(LAMBDA (x, y) (- (* x x x) (* y y) ) )

Front 3

If a language treats functions the same way it treats data, then functions are said to be

Back 3

first-class entities

Front 4

One of the main reasons that functional languages have not had the success that imperative languages have enjoyed is that

Back 4

imperative languages are much more strongly matched to the capabilities of the underlying hardware

Front 5

Assuming n is a positive integer, what is returned by (define (fib n) (if (= n 1) n (* n (fib (- n 1) ) ) ) )?

Back 5

the factorial of n

Front 6

Scheme language requires that ( ) functions be converted to iterative implementations

Back 6

tail-recursive

Front 7

The EVAL function, by itself, serves as

Back 7

a LISP interpreter

Front 8

A function that returns a Boolean value is known as

Back 8

a predicate function

Front 9

The basic data structure in LISP/Scheme?Racket is

Back 9

the cons cell

Front 10

What will be the result of (cons (list (cons 1 2) 3 4 ) 5) ?

Back 10

( ( (1 . 2) 3 4) . 5)

Front 11

A nameless function is known as

Back 11

a lambda function

Front 12

A function that can take a function as an argument and/or return a function as its result is known as

Back 12

a higher-order function

Front 13

Iteration is implemented in a functional language via

Back 13

recursion

Front 14

If a function always returns the same value, given the same parameters (and has no side effects), it is said to be

Back 14

referentially transparent

Front 15

The three flow control mechanism provided by Scheme are

Back 15

IF, COND, and recursion

Front 16

The name used to describe having multiple ways to accomplish the same task is

Back 16

feature multiplicity

Front 17

When there are few restrictions on how primitive constructs can be combined, the language is said to be

Back 17

orthogonal

Front 18

Which of the following are the three primary categories of languages, per the author?

Back 18

imperative, functional, and logical

Front 19

A general observation that is true more often than not regarding language design decisionsis that

Back 19

improvement in one area often requires sacrifice in another.

Front 20

When two or more identifiers access the same memory cell, this is known as

Back 20

aliasing.

Front 21

The smallest parts of a language, such as operators, special words, numeric values, arecalled

Back 21

lexemes.

Front 22

Categories of lexemes are called

Back 22

tokens.

Front 23

The 'syntax' of a programming language is

Back 23

the form of its expressions, statements, and program units.

Front 24

The 'semantics' of a programming language is

Back 24

the meaning of its expressions, statements, and program units.

Front 25

The language described by a grammar

Back 25

is independent of the manner (order) in which rules are applied.

Front 26

A language recognizer performs what task?

Back 26

Answers the question of whether a particular sentence is a member of a particularlanguage.

Front 27

A parser performs what task?

Back 27

Creates a hierarchical description of the grammatical structure of a sentence.

Front 28

A lexer performs what task?

Back 28

Reduces a sentence into a stream of tokens.

Front 29

A context free grammar imposes precedence of operators by placing

Back 29

lower precedence operators closer to the Start symbol in the production chain.

Front 30

The strings that can be produced by a language are called

Back 30

sentences.

Front 31

The rules of a context free grammar are known as

Back 31

productions.

Front 32

Which of the following is NOT a trait of identifiers in most programming languages?

Back 32

The name may contain digits in any position.

Front 33

A language is considered ambiguous if

Back 33

a given sentence can be represented by two different parse trees.

Front 34

The production: "Bob: Sue op Bob" enforces

Back 34

right associatively of Bob.

Front 35

A "terminal" in a grammar is

Back 35

an element consisting of a token or literal lexeme.

Front 36

Which is NOT true regarding the "dangling else" (a.k.a. "else-association") problem?

Back 36

This is inherently ambiguous in any language that does not have an "end-if" orequivalent keyword.

Front 37

Which of the following is NOT a reason given by the author for studying the concepts ofprogramming languages?

Back 37

Improved ability to understand poorly written code.

Front 38

The main reason that no single language has come to dominate all of programming is that

Back 38

language selection criteria are largely self-contradictory and highly context dependent.

Front 39

What is the principal problem with left-recursive productions?

Back 39

Some important syntax analysis algorithms cannot be used with grammars containing suchproductions.

Front 40

Which of the following is not a primary criterion, per the author, for selecting aprogramming language?

Back 40

Scalability.

Front 41

The name used to describe having multiple ways to accomplish the same task is

Back 41

feature multiplicity.

Front 42

When there are few restrictions one how primitive constructs can be combined, the languageis said to be

Back 42

orthogonal.

Front 43

Which language category is generally the most influenced by the underlying hardwarearchitecture?

Back 43

Imperative.

Front 44

When complicated data structures and operations can be built that allow the underlyingdetails to be ignored when used is an example of

Back 44

abstraction.

Front 45

The reliability of a program is significantly affected by all but which of the following?

Back 45

An optimizing compiler.

Front 46

The total cost of a programming language is a strong function of all of the following except

Back 46

the ability to run the same executable on different operating systems.

Front 47

Much of the evolution in program language design has been motived by the

Back 47

shift in the major cost of computing from hardware to software.

Front 48

Which of the following is NOT true about programming language needs at the present time

Back 48

computing power has reached a point that unsafe languages such as C should never beused for new code.

Front 49

The use of purely interpreted languages has seen a comeback in recent years in part because

Back 49

the processing speed and memory available to support interpretation has improveddramatically.

Front 50

The use of intermediate code running on a virtual machine greatly facilites

Back 50

platform portability.

Front 51

Which type of variable has the storage binding and lifetime normally associated with"automatic" variables?

Back 51

Stack-dynamic.

Front 52

The use of functions such as malloc() and free() are used with which type of variable?

Back 52

Explicit heap-dynamic.

Front 53

The term "static" generally implies

Back 53

that the associated attribute is known prior to runtime and does not change once theprogram has started running.

Front 54

The term used to describe the specification of a variables type and other attributes notincluding storage allocation is

Back 54

declaration.

Front 55

The term used to describe the specification of a variables type and other attributesincluding storage allocation is

Back 55

definition.

Front 56

Which of the following is NOT true: Compared to dynamicly scoped languages, staticallyscoped languages

Back 56

require fewer parameters to be passed to functions.

Front 57

The referencing environment of a statement is

Back 57

the collection of all variables that are visible in that statement.

Front 58

Which of the follow is NOT a means that was discussed for how a language might determinevariable type?

Back 58

Value of a leading digit in the variable name.

Front 59

Which of the following is NOT true of dynamic type binding?

Back 59

Type checking must be done at compile time.

Front 60

What is a reserved word in a language definition?

Back 60

A word that, although otherwise valid, cannot be used as a name (variable or function).

Front 61

The attributes that are bound to a variable are

Back 61

name, address, value, type, lifetime, and scope.

Front 62

The address of a variable is sometimes called its

Back 62

lvalue.

Front 63

Decimal data types are intended to

Back 63

store decimal values, including fractional values, exactly over some range.

Front 64

A reference to a substring is typically called a

Back 64

slice.

Front 65

Which of the following is NOT an ordinal type?

Back 65

string

Front 66

Signed integer data types most typically use which of the following internal representations?

Back 66

Twos complement.

Front 67

An array in which the binding of both the subscript range and memory allocation occursbefore execution is a

Back 67

static array.

Front 68

When two operators of the same precedence are adjacent in an expression, evaluation isperformed

Back 68

according to the associativity of the operators.

Front 69

Most programming languages use which ordering notation for binary operations?

Back 69

infix.

Front 70

What is a "side effect"?

Back 70

When the evaluation of an expression changes the value of a variable.

Front 71

What is "referential transparency" refer to?

Back 71

When any two expressions that produce the same value can be substituted for each otheranywhere in a program.

Front 72

What is an alias?

Back 72

One or more additional variable names that refer to the same memory location.

Front 73

When variables are bound to a type through default conventions, this is known as

Back 73

implicit declaration.

Front 74

When a variable is assigned a type based on the context of it use, this is known as

Back 74

type inference.

Front 75

In most languages, variables that are local to functions have what kind of storage binding?

Back 75

Stack-dynamic.

Front 76

The scope of a variable is

Back 76

the range of statements in which the variable is visible.

Front 77

What distinguishes static (lexical) scoping from dynamic scoping?

Back 77

Static scoping can be determined prior to execution while dynamic scoping can only bedetermined at run time.

Front 78

A data type can be described as

Back 78

a collection of data values and a set of predefined operations on those values.

Front 79

The type system of a programming language does all of the following except

Back 79

restricts the programmer to using only predefined types that have been marked safe.

Front 80

Primitive data types

Back 80

are those data types that are not defined in terms of other data types.

Front 81

Which of the following statements regarding string data types is true.

Back 81

String data types vary significantly from one language to another.

Front 82

How is the length of a string determined in the C programming language?

Back 82

A sentinel value, null, is placed in an array after the last character in the string.

Front 83

An enumeration type is generally

Back 83

a set of named constants.

Front 84

The following are all significant design issues for arrays except:

Back 84

Should array elements be homogeneous (i.e., all of the same type)?

Front 85

A type who variables may store different data types at different times is known as a

Back 85

union.

Front 86

What is a "dangling pointer"?

Back 86

A pointer that refers to a heap-dynamic variable that has been deallocated.

Front 87

What does "lost memory" refer to?

Back 87

A block of allocated memory that is no longer accessible to a user program.

Front 88

Floating point data types most typically use which of the following internal representations?

Back 88

IEEE-754

Front 89

Which of the following statements is NOT true regarding operator overloading:

Back 89

Overloaded operators always operate on user-defined data types.

Front 90

A type conversion to a type that cannot store even approximations of all of the values ofthe original type is

Back 90

a narrowing conversion.

Front 91

Implicit type conversions performed transparently by the compiler are referred to as

Back 91

coersions.

Front 92

Errors such as overflow, underflow, and division by zero, are

Back 92

called run-time errors or exceptions.

Front 93

Relational operators

Back 93

are almost always of a lower precedence than the arithmetic operators.

Front 94

In C, if a=6, b=4, and c=2, the result of evaluating a < b < c will be

Back 94

1

Front 95

Short-circuit evaluation is when

Back 95

an operand of an expression may not be evaluated if the expression result can bedetermined by the other operand.

Front 96

In C, the statement a=b+c=d+e will produce the same result as

Back 96

this is a syntax error in C.

Front 97

The C statement a=(b=c)?3:2; will result in what value assigned to 'a' if b=0 and c=0?

Back 97

3

Front 98

Compound assignment operators

Back 98

are a shorthand method of specifying common used expressions.

Front 99

An assignment statement with a conditional target means that

Back 99

the variable that a value is assigned to depends on the evaluation of an expression.

Front 100

Mixed-mode assignments that disallow narrowing coersions

Back 100

increase the reliability of a language.

Front 101

A function prototype in C/C++ is another term for a function's

Back 101

declaration.

Front 102

In object-oriented languages, a "method" generally refers to a subprogram that is

Back 102

called from an instance of class and has access to all of that instance's data.

Front 103

A generic subprogram is one whose

Back 103

computation can be done on data of different types in different calls.

Front 104

A 'closure' is a

Back 104

nested subprogram combined with its referencing environment.

Front 105

Which of the following parameter passing schemes ensures that the subprogram is notcapable of changing variables seen by the caller?

Back 105

pass-by-value

Front 106

Which of the following parameter passing schemes gives gives rise to issues associatedwith aliases?

Back 106

pass-by-reference

Front 107

Which parameter passing scheme is often used by compilers for generic parameters but isotherwise not part of any widely used modern langauges.

Back 107

pass-by-name

Front 108

Because C uses row-major array indexing, which of the following is a workable headerfor passing an 20-row, 10-col array to a function?

Back 108

void fun(int matrix[][10]) {...}

Front 109

The method of establishing the referencing environment for nested subprograms instatically-scoped languages is almost always

Back 109

deep binding.

Front 110

In C/C++, it is possible to pass functions as arguments to functions through the use of

Back 110

function pointers.

Front 111

An activation record is a data structure that holds all but which of the followinginformation about a function call?

Back 111

Static local variables.

Front 112

An activation record is almost always located

Back 112

on the function call stack.

Front 113

In an activation record, the pointer to the base of the activation record of the calleris known as

Back 113

a dynamic link.

Front 114

In an activation record, the pointer to the base of the activation record for the mostrecently called lexical parent of the called program is known as

Back 114

a static link.

Front 115

In an activation record, the location in the code at which to resume execution once thecalled program terminates is known as

Back 115

the return address.

Front 116

What is the only difference, in terms of the activation record instances, when asubprogram makes a recursive call to itself?

Back 116

There is no difference

Front 117

The dynamic link, in static-scoped languages, is used to

Back 117

provide traceback information when a run-time error occurs.

Front 118

The dynamic link, in dynamic-scoped languages, is used to

Back 118

access nonlocal variables.

Front 119

The static link, in static-scoped languages, is used to

Back 119

access nonlocal variables.

Front 120

Which element is not needed in an activation record when subprograms cannot be nested?

Back 120

A static link.

Front 121

Blocks (compound statements) that provide user-specified local scopes can beimplemented as

Back 121

parameterless nested subprograms, even in languages that don't support nestedsubprograms.

Front 122

Blocks within a subprogram can be implemented

Back 122

by including any block variables as part of the subprogram's set of local variables onthe stack

Front 123

Dynamic scoping that is implemented via tracing through the activation records for thenearest instance of a variable name is known as

Back 123

deep access.

Front 124

Dynamic scoping that is implemented via maintaining a separate stack for each namedvariable is known as

Back 124

shallow access.

Front 125

A "central table" is one alternative method of implementing

Back 125

shallow access.

Front 126

In most languages, when a function terminates the caller sees the return value

Back 126

on top of the stack.

Front 127

The semantics of the call to a "simple" subprogram (no nesting and only static localvariables) require all of the following actions except

Back 127

saving the execution status of the current program unit.

Front 128

The semantics of the return from "simple" subprogram (no nesting and only static localvariables) require all of the following actions except

Back 128

deallocating memory on the stack for the local variables.

Front 129

In some processors, particularly RISC processors, subprogram parameters are not passedon the stack but, instead, via

Back 129

processor registers.

Front 130

A subprogram is 'active'

Back 130

from the time it is called until the time it terminates.

Front 131

Deep access and shallow access

Back 131

are two different ways of implementing the same access semantics for non-localvariables in a dynamically-scoped language.

Front 132

The two-way selection statement is commonly known as

Back 132

the if-then-else structure.

Front 133

The ambiguous-else (or dangling-else) problem is generally resolved by what rule?

Back 133

each 'else' clause is paired with the most recent unpaired 'if' expression.

Front 134

The multiple selection statement is commonly known as

Back 134

the switch structure.

Front 135

When control flows from one case label to the next, this is known as

Back 135

flow-through.

Front 136

In C, if a switch expression does not have a 'default' case, then

Back 136

the entire construct is skipped if none of the case labels match the expression.

Front 137

Which of the following is NOT true regarding switch statements in C:

Back 137

case labels can cover a range of values.

Front 138

Iterative statements are broadly categorized as belong to one of which two categories?

Back 138

Counter-controlled and Logically controlled.

Front 139

In C, which of the following is true of the looping constructs?

Back 139

Any loop that can be written using one construct can be implemented using either of theremaining constructs.

Front 140

With the C 'for' statement, which of the following statements is NOT true?

Back 140

An infinite loop results if the 'for' header's the test expression (the middleexpression) is left out.

Front 141

What is perhaps the single strongest reason that the 'break' statement is includedinstead of using a 'goto' statement?

Back 141

The 'goto' statement is highly unstructured while the 'break' statement's restrictionskeep the code readable.

Front 142

Most modern languages still include a 'goto' statement (or equivalent) for what reason?

Back 142

There are situations in which the judicious use of a 'goto' statement is reasonable andremains readable.

Front 143

In addition to sequences, what two control structures are absolutely required toexpress computation?

Back 143

Selection and pre-test loops.

Front 144

Data-based control structures designed to execute the loop body one time for each data element are generally known as

Back 144

iterators.

Front 145

In many processors, particularly simple ones, all of the control structures in alanguage are ultimately implemented using

Back 145

conditional and unconditional branch (i.e., goto) instructions.

Front 146

Why do most languages include more control statements than are absolutely required forcompleteness?

Back 146

Readability and writability.

Front 147

The method used by some languages to eliminate the ambiguous-if problem syntacticallyis to require

Back 147

the use of a reserved word to close the selection entity explicitly.

Front 148

In pure functional programming languages, counter controlled loops are generallyimplemented

Back 148

using recursion.

Front 149

Hardware support for looping structures is problematic in practice because

Back 149

hardware design and language design are difficult to coordinate over a sufficientlylong time.

Front 150

Which of the following statement concerning goto statements is false?

Back 150

Since all hardware architecture is based on conditional and unconditional branches, allmodern languages support the goto statement.

Front 151

Except for coroutines, subprograms in modern languages generally have all of the following characteristics except:

Back 151

a single exit point.

Front 152

The general distinction between a "procedure" and a "function" is that

Back 152

functions return values while procedures do not.

Front 153

The parameters in a subprogram header are called

Back 153

formal parameters.

Front 154

In most languages, formal and actual parameters are bound together by

Back 154

position.

Front 155

The referencing environment of a subprogram

Back 155

is the collection of variables that can be accessed by statements within that subprogram.

Front 156

A subprogram's local variables are generally either

Back 156

static or stack-dynamic.

Front 157

Which parameter passing scheme is also known as pass-by-copy?

Back 157

Pass-by-value-result

Front 158

Which parameter passing scheme is primarily used for situations in which no values need be passed to the subprogram, but rather only values need to be passed back to the caller?

Back 158

Pass-by-result

Front 159

Most parameter passing schemes are implemented via

Back 159

the function call stack.

Front 160

Ensuring that formal and actual parameters are consistent is the role of

Back 160

type checking.

Front 161

In most languages, when a function terminates the caller sees the return value

Back 161

on top of the stack.

Front 162

Dynamic scoping that is implemented via tracing through the activation records for thenearest instance of a variable name is known as

Back 162

deep access.

Front 163

The act of creating an abstract data type and hiding its implementation details isgenerally referred to as

Back 163

encapsulation.

Front 164

An abstract data type includes

Back 164

a representation of the data as well as the processes that act upon that data.

Front 165

A primary motivator for data abstraction is to

Back 165

manage complexity.

Front 166

The problem of different programmers calling their methods or classes the same thing ismitigated through the use of

Back 166

namespaces.

Front 167

To qualify as an abstract data type, all of the following must be true except:

Back 167

the internal representation must be clearly defined and documented.

Front 168

When access to internal data members is needed, accessor methods (getters and setters) areused for all of the following reasons except.v

Back 168

accessor methods provide fast, efficient access to data members without the functioncall overhead that would otherwise be involved.

Front 169

The act of creating an abstract data type and hiding its implementation details isgenerally referred to as

Back 169

encapsulation.

Front 170

An abstract data type includes

Back 170

a representation of the data as well as the processes that act upon that data.

Front 171

What is an 'abstraction'?

Back 171

A representation that includes only the most significant parts.

Front 172

A functions or procedure can generally be classified as a

Back 172

process abstraction.

Front 173

Most floating-point data types qualify as an abstract data type for all of the followingreasons except:

Back 173

the data type has been standardized as part of the IEEE-754 floating point standard.

Front 174

The name that is usually used to describe subprograms that are only accessible to othersubprograms that are part of the same abstract data type is

Back 174

private.

Front 175

The name that is usually used to describe subprograms that are accessible to subprogramsthat use an abstract data type is

Back 175

public.

Front 176

In object-oriented terminology, a 'method' is a subprogram

Back 176

that is specific to a class and can only be invoked via an instance of an object of

Front 177

A 'constructor' is a method that

Back 177

is called whenever a new instance of a class object is created.

Front 178

A 'destructor' is a method that

Back 178

is called whenever an instance of a class object is deleted.

Front 179

Destructors are rarely used in C# because

Back 179

the use of garbage collection makes the timing of when a destructor is executedunpredictable.

Front 180

The purpose of having parameterized abstract data types is

Back 180

to allow a generically defined data type be able to handle actual data of various types.

Front 181

What is a reserved word in a language definition?

Back 181

A word that, althoughotherwise valid, cannot be used as a name (variable or function).