Programming Languages

Front 1

The activity of ensuring that the the operands of an operator are of compatible types

Back 1

type checking

Front 2

The range of statements in which the variable is visible

Back 2

scope

Front 3

A variable that can be referenced in that statement

Back 3

visible

Front 4

The method of binding names to nonlocal variables

Back 4

static scoping

Front 5

When the scope can only be determined at runtime

Back 5

dynamic scoping

Front 6

The collection of all variables that are visible in the statement

Back 6

referencing environment

Front 7

A variable that is bound to a value only once

Back 7

named constant

Front 8

Named constants in languages that use static binding of values

Back 8

manifest constant

Front 9

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

Back 9

data types

Front 10

The collection of the attributes of a variable

Back 10

descriptor

Front 11

The most common primitive numeric data type

Back 11

integer

Front 12

Data types that are not defined in terms of other types

Back 12

primitive data type

Front 13

The simplest of all data types

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boolean

Front 14

A type in which the variables have a wide range of values that consist of memory addresses and a special value, nil

Back 14

pointer

Front 15

When a pointer can be used to access a location in the area where storage is dynamically allocated

Back 15

heap

Front 16

Variables that are no longer accessible to the user program.

Back 16

garbage

Front 17

This type refers to an object or value in memory

Back 17

reference

Front 18

Name several proposed solutions to the dangling-pointer problem

Back 18

tombstone, locks-and-keys

Front 19

the range of statements over which it is visible

Back 19

variable scope

Front 20

define implicit heap-dynamic and list the advantages and disadvantages of both

Back 20

-allocation and deallocation caused by assignment statements
-advantages:flexibility
-disadvantages: inefficient bc all attributes are dynamic; loss of error detection

Front 21

define explicit-heap-dynamic variables and list the advantages and disadvantages of each

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-allocated and deallocated by explicit directives, specified by the programmer, which take effect during execution
-advantages:provides for dynamic storage management
-disadvantaged:inefficient and unreliable

Front 22

the range of statements over which it is visible

Back 22

variable scope

Front 23

define implicit heap-dynamic and list the advantages and disadvantages of both

Back 23

-allocation and deallocation caused by assignment statements
-advantages:flexibility
-disadvantages: inefficient bc all attributes are dynamic; loss of error detection

Front 24

define explicit-heap-dynamic variables and list the advantages and disadvantages of each

Back 24

-allocated and deallocated by explicit directives, specified by the programmer, which take effect during execution
-advantages:provides for dynamic storage management
-disadvantaged:inefficient and unreliable

Front 25

name several proposed solutions to the dangling pointer problem

Back 25

tombstones, locks and keys

Front 26

a type in which the variables have a wide range of values that consists of memory addresses and a special value, nil

Back 26

pointer

Front 27

named constants in languages that use static binding of value

Back 27

manifest constants

Front 28

a pointer that contains the address of a heap-dynamic variable that has been deallocated

Back 28

dangling pointer

Front 29

activity of ensuring that the operands of an operator are of compatible types

Back 29

type checking

Front 30

when the memory cell to which a variable is bound somehow must be taken from a pool of available memory

Back 30

allocation

Front 31

time during which the variable is bound to a specific memory location

Back 31

lifetime

Front 32

an abstraction of a memory cell

Back 32

variable

Front 33

name the six attributes of a variable

Back 33

-name
-address
-value
-type
-lifetime
-scope

Front 34

what is the l-value, and the r-value of a variable

Back 34

the l-value is its address and the r-value it its value

Front 35

an association such as between an attribute and an entity or between an operation and a symbol

Back 35

binding

Front 36

the time at which binding takes place

Back 36

binding time

Front 37

a type of binding that occurs before run time and remains unchanged throughout program execution

Back 37

static binding

Front 38

first occurs during execution or can change during execution of a program

Back 38

dynamic binding

Front 39

after language design and implementation, what are the four time bindings that can take place in a program

Back 39

-compile time
-lead time
-link time
-run time

Front 40

what are the design issues for names

Back 40

-case sensitivity
-special words
-reserved words
-keywords

Front 41

what is the potential danger of case sensitive names

Back 41

-violates the design principle that language constructs that look similar should have similar meanings

Front 42

In what ways are reserved words better than keywords

Back 42

-the ability to redefine keywords can be confusing

Front 43

which category of C++ reference variables is always aliases

Back 43

pointers

Front 44

when more than one variable can be used to access the same memory location

Back 44

alias

Front 45

a special word of a programming language that cannot be used as a name

Back 45

reserved word

Front 46

a word of a programming language that is special only in certain contexts

Back 46

keywords

Front 47

name the primitive data types

Back 47

-int
-float
-complex
-decimal
-boolean
-character

Front 48

those not defined in terms of other data types

Back 48

primitive data type

Front 49

represents an instance of a user-defined (abstract data) type

Back 49

object

Front 50

what are the main design issues for all data types

Back 50

-what operations are defined
-how are they specified

Front 51

a collection of data objects and a set of predefined operations on those objects

Back 51

data types

Front 52

the collection of the attributes of a variable

Back 52

descriptor

Front 53

the contents of the memory cell or cells associated with the variable

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variable value

Front 54

determines the range of values the variable can store and the set of operations that are defined for values of the type

Back 54

variable type

Front 55

a variable that is bound to a value only when it is bound to storage

Back 55

named constant

Front 56

what is the advantage of a named constant

Back 56

-readability & modifiability
-used to parameterize programs

Front 57

what are the advantages and disadvantages of dynamic scoping

Back 57

-advantage:convenience
-disadvantage:while in a subprogram is executing, its variables are visible to all subprograms it calls; impossible to statically type check; poor readability bc it is not possible to determine the type of the variable

Front 58

what are the advantages and disadvantages of static scoping

Back 58

-advantage: works well with many situations
-disadvantage: too much access is possible as a program evolves, the initial structure is destroyed and local variables often become global; subprograms also gravitate toward becoming global rather than nested

Front 59

in this language a global variable can be assigned a function only if it has been declared to be global in a function

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python

Front 60

in this language global variables can be accessed in a function through the $GLOBALS array or by declaring it global

Back 60

PHP

Front 61

in these languages a declaration outside a function definition specifies that it is defined in another file

Back 61

C, C++

Front 62

these languages allow variable declarations to appear outside function definitions

Back 62

C, C++, PHP, Python

Front 63

distinguish between a lexer and a parser

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-a lexer is a low-level part called a lexical analyzer that matches patterns for character strings
-a parser is a high-level part (syntax analyzer) that finds all syntax errors and produces the parse tree

Front 64

describes the meaning of a statement or program by giving the effects of running it on a machine

Back 64

operational semantics

Front 65

uses functions to map language to meaning

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denotational semantics

Front 66

this is based on mathematical logic and is the most abstract, states what can be proven about the program

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axiomatic semantics

Front 67

most commonly used coding for characters that was ____ code

Back 67

8-bit ascii

Front 68

currently a code called ______ with 16-bits is often used

Back 68

unicode

Front 69

what is the difference between syntax and semantics

Back 69

-syntax is the form of its expressions,statement, and program units
-semantics are the meanings of those expressions, statements, and program units

Front 70

what does PERL stand for

Back 70

practical extraction and report language

Front 71

what is the first high level programming language

Back 71

FORTRAN

Front 72

the collection of all names that are visible in the statement

Back 72

referencing environment

Front 73

based on the calling sequence of subprograms and can only be determined at run time

Back 73

dynamic scope

Front 74

define static variable and list the advantages and disadvantages of each

Back 74

-is bound to a memory cell before execution begins and remains bound to the same memory cell throughout execution
-advantages: efficiency and history sensitive subprogram support
-disadvantage: lack of flexibility (no recursion)

Front 75

define stack-dynamic variable and list the advantages and disadvantages

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-when storage bindings are created for variables when their declarations statements are elaborated (when the executable code associated with it is executed)
-advantage:allows recursion, conserves storage
-disadvantage:overhead of allocation and deallocation

Front 76

when the scope of a variable can be statically determined prior to program execution

Back 76

static scope

Front 77

the time during which the variable is bound to a specific memory location

Back 77

lifetime

Front 78

variables that are visible but are not declared there

Back 78

nonlocal variables

Front 79

who created Scheme

Back 79

Sussman and Steele in 1975 MIT

Front 80

what are the design issues for the string type

Back 80

-Should strings be simply a kind of character array or a primitive type
-should strings have static or dynamic length

Front 81

what are the design issues for arrays

Back 81

-what types are legal for subscripts
-are subscripting expressions in element references range checked
-when are subscript ranges bound
-when does an array allocation take place
-are ragged or rectangular multidimensioned arrays allowed, or both
-can arrays be initialized when they have their storage allocated
-what kind of slices are allowed if any

Front 82

a type whose variable may store different type values at different times during program execution

Back 82

union

Front 83

what are the design issues for unions

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-should type checking be required
-should unions be embedded in records

Front 84

an aggregate of data elements in which the individual elements are identified by names and accessed through offsets from the beginning of the structure

Back 84

record

Front 85

what are the design issues of pointers

Back 85

-what are the scope and lifetime of a pointer variable
-what is the lifetime of a heap-dynamic variable
-are pointers restricted as to the type of value to which they can point
-are pointers used for dynamic storage management, indirect addressing, or both
-should the language support pointer types, reference types, or both

Front 86

the means of choosing between two or more execution paths in a program

Back 86

selection statement

Front 87

example of a two-way statement

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if statement

Front 88

what are the design issues of a two-way selection statement

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-what is the form and type of expression that controls the selection
-how are the then and else clause specified
-how should the meaning of nested selectors be specified

Front 89

allows the selection of one of any number of statements or statement groups

Back 89

multiple selection construct

Front 90

what are the design issues of a multiple selection construct

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-what is the form and type of the expression that controls the selection
-how are the selectable segments specified
-is execution flow through the structure restricted to include just a single segment
-how are the case values specified
-how should unrepresented selector expression values be handles, if at all

Front 91

causes a statement or collection of statements to be executed to zero, one, or more times

Back 91

iterative statement

Front 92

what are the design issues of iterative statements

Back 92

-how is iteration controlled
-where should the control mechanism appear in the loop construct

Front 93

when the repetition control is based on a Boolean expression rather than a counter

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logically controlled loops

Front 94

what are the design issues for a logically controlled lop

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-should the control be pretest or posttest
-should the logically controlled loop be a special form of a counting loop or a seperate statement

Front 95

transfers execution control to a specified location in the program

Back 95

unconditional branch statement

Front 96

each line in a selection construct consisting of a Boolean expression (a guard) and a statement or statement sequence

Back 96

guarded command

Front 97

a nameless function in Scheme

Back 97

lambda expression