Programming Languages

What is aliasing?

Aliasing means having two different names for one memory location. Mostly all languages support aliasing up to different extents and in different ways. Aliasing is considered a very dangerous feature and should be used cautiously. It is known to decrease the reliability of the program.

Why is readability important to writability?

Both reliability and writ-ability greatly affects reliability of a program. A language which uses non natural keyword or statements to write algorithms is more likely to be error prone.

In what language is most of UNIX written?

C

What programming language has dominated business applications over the past 50 years?

COBOL

Which produces faster program execution, a compiler or a pure interpreter?

Compiler is faster than a pure interpreter. It is because a compiler translates the whole code into machine language then executes it, while pure interpreter translates each statement to machine code each time the statement is executed

Reliability refers to The ease with which programs can be read and understood The ultimate total cost The ease with which a language can be used to create programs Conformance to specifications

Conformance to specifications

What is exception handling?

The ability of a program to intercept unusual conditions at the runtime, take corrective measures and then continue without crashing is called exception handling.

What role does the symbol table play in a compiler?

The symbol table is a database for compilation. It contains the type and attribute information of user-defined names in a program.

How can user-defined operator overloading harm the readability of a program?

This will sometimes lead to reduced readability. + can mean two different things in program.

Why is the von Neumann bottleneck important?

We can provide a Von Neumann processor with more cache, more RAM, or faster components but if original gains are to be made in CPU performance then an influential inspection needs to take place of CPU configuration. This architecture is very important and is used in our PCs and even in Super Computers.

What programming language has dominated scientific computing over the past 50 years?

fortran

What is the name of the category of programming languages whose structure is dictated by the von Neumann computer architecture?

imperative languages

What does a linker do?

linker or link editor is a computer utility program that takes one or more object files generated by a compiler and combines them into a single executable file, library file, or another 'object' file.

What programming language has dominated artificial intelligence over the past 50 years?

lisp, C now

What are the advantages in implementing a language with a pure interpreter?

platform independence easier to debug and easier to get source code smaller in size automatic memory management

What is the disadvantage of having too many features in a language?

the readability and understandably of a languages is decreased as a reader may not have knowledge of all features.

A compiled language executes faster than an interpretive language. t or f

true

Execution cost of reliable programming languages is usually higher than that of other types of programming languages. 1) True 2) False

true

There is no translation involved in a pure interpretive language. t or f?

true

Studying concepts of programming languages would allow for -Better understanding of significance of implementation -Improved background for choosing appropriate languages -Increased ability to learn new languages -Better use of languages that are already known

-Better understanding of significance of implementation -Improved background for choosing appropriate languages -Increased ability to learn new languages -Better use of languages that are already known

Following are some programming language evaluation criteria: Correct Response 1) Reliability 2) Readability 3) Cost 4) Writability 5) Portability

1) Reliability 2) Readability 3) Cost 4) Writability 5) Portability

Following are phases of compilation: Correct Response 1) Syntax analysis 2) Code generation 3) Semantics analysis 4) Lexical analysis

1) Syntax analysis 2) Code generation 3) Semantics analysis 4) Lexical analysis

What are the three general methods of implementing a programming language?

1- Compiler Implementation 2- Just In Time (JIT) or Interpreted implementation 3- The combination of both compiled and interpreted implementation.

What is an example of two language design criteria that are in direct conflict with each other?

1- cost of execution 2- reliability

What two programming language deficiencies were discovered as a result of the research in software development in the 1970s?

1- lack of type checking can lead to unreliability of the code 2- inadequacy of control statements requiring extensive usage of goto statements.

What are the three fundamental features of an object-oriented programming language?

1: Data Abstraction - It encapsulated the data and its associated processes together and also controls access to data. 2: Inheritance- It enchances the potential reuse of existing software thereby increasing the software development productivity. 3: Dynamic Method Binding or Polymorphism - It allows for more flexible use of inheritance.

Who is more concerned about writability and readability of programming languages? 1) Language implementers 2) Language users 3) Neither of the listed groups 4) Language designers

2) Language users

What does it mean for a program to be reliable?

A program is said to be reliable if under all conditions, the program performs according to its specifications.

What have been the strongest influences on programming language design over the past 50 years?

Influence of Von Neumann Architecture - uses single memory to store data as well as programs ans a processor to perform computations.

Why is it useful for a programmer to have some background in language design, even though he or she may never actually design a programming language?

It is advised for programmers to have some background in languages design even though most of them are never going to design a language. There are a variety of benefits by learning about the coir idea behind the language design. It'll be easier to learn the philosophy behind all languages because all languges are governed by a set of universal principles.

How can knowledge of programming language characteristics benefit the whole computing community?

Knowledge of the programming language characteristics can aid the whole computing community. Also, the knowledge of the characteristics of the programming languages make one a better programmer. If the programmers know the implementation details of some construct they can understand for what tasks need to be done for efficiency purposes.

How is the cost of compilers for a given language related to the design of that language?

Language design depends upon the cost of variety of things. 1- the first is the cost of training programmers in that particular language. 2- another reason is cost of 4-writing code or development in that language. 3- cost of compiliation and cost of language implemetation systems. It mainly depends upon the writability of the language.

What is one example of a lack of orthogonality in the design of C?

Orthogonality means the primitive constructs of a language can be combined in all possible combinations without any exceptions. Lack of Orthogonality will lead to exceptions in a language which will make the language difficult to learn.

What language was the first to support the three fundamental features of object-oriented programming?

Smalltalk

What language used orthogonality as a primary design criterion?

assembly languages

What primitive control statement is used to build more complicated control statements in languages that lack them?

available control statement

The following is an example of a Systems Programming language: 1) FORTRAN 2) LISP 3) COBOL 4) C

c