PRACTICE: Presente simple COMPUTER LANGUAGE SINTAX

COMPUTER LANGUAGE SINTAX
Every spoken language has a general set of rules for how words and sentences should be structured. These rules are collectively known as the language syntax. In computer programming, syntax serves the same purpose, defining how declarations, functions, commands, and other statements should be arranged.
Many computer programming languages share similar syntax rules, while others have a unique syntax design. For example, C and Java use a similar syntax, while Perl has many characteristics that are not seen in either the C or Java languages.
A program's source code must have correct syntax in order to compile correctly and be made into a program. In fact, it must have perfect syntax, or the program will fail to compile and produce a "syntax error." A syntax error can be as simple as a missing parenthesis or a forgotten semicolon at the end of a statement. Even these small errors will keep the source code from compiling.
Fortunately, most integrated development environments (IDEs) include a parser, which detects syntax errors within the source code. Modern parsers can even highlight syntax errors before a program is compiled, making it easy for the programmer to locate and fix them.
NOTE: Syntax errors are also called compile-time errors, since they can prevent a program from compiliing. Errors that occur in a program after it has been compiled are called runtime errors, since they occur when the program is running.

SOURCE CODE
Every computer program is written in a programming language, such as Java, C/C++, or Perl. These programs include anywhere from a few lines to millions of lines of text, called source code.
Source code, often referred to as simply the "source" of a program, contains variable declarations, instructions, functions, loops, and other statements that tell the program how to function. Programmers may also add comments to their source code that explain sections of the code. These comments help other programmers gain at least some idea of what the source code does without requiring hours to decipher it. Comments can be helpful to the original programmer as well if many months or years have gone by since the code was written.
Short programs called scripts can be run directly from the source code using a scripting engine, such as a VBScript or PHP engine. Most large programs, however, require that the source code first be compiled, which translates the code into a language the computer can understand. When changes are made to the source code of these programs, they must be recomplied in order for the changes to take effect in the program.
Small programs may use only one source code file, while larger programs may reference hundreds or even thousands of files. Having multiple source files helps organize the program into different sections. Having one file that contains every variable and function can make it difficult to locate specific sections of the code. Regardless of how many source code files are used to create a program, you will most likely not see any of the original files on your computer. This is because they are all combined into one program file, or application, when they are compiled.

READING COMPREHENSION: THE PARADIGMS OF PROGRAMMING

The Paradigms of Programming

                  A familiar example of a paradigm of programming is the technique of structured programming, which appears to be the dominant paradigm in most current treatments of programming methodology. Structured programming, as formulated by Dijkstra [6], Wirth [27, 29], and Parnas [21], among others, consists of two phases.
In the first phase, that of top-down design, or stepwise refinement, the problem is decomposed into a very small number of simpler subproblems. In programming the solution of simultaneous linear equations, say, the first level of decomposition would be into a stage of triangularizing the equations and a following stage of back-substitution in the triangularized system. This gradual decomposition is continued until the subproblems that arise are simple enough to cope with directly. In the simultaneous equation example, the back substitution process would be further decomposed as a backwards iteration of a process which finds and stores the value of the ith variable from the ith equation. Yet further decomposition would yield a fully detailed algorithm.
                  The second phase of the structured programming paradigm entails working upward from the concrete objects and functions of the underlying machine to the more abstract objects and functions used throughout the modules produced by the top-down design. In the linear equation example, if the coefficients of the equations are rational functions of one variable, we might first design a multiple-precision arithmetic representation and procedures, then, building upon them, a polynomial representation with its own arithmetic procedures, etc. This approach is referred to as the method of levels of abstraction, or of information hiding.

                Other high level paradigms of a more specialized type, such as branch-and-bound [17, 20] or divide-and-conquer [1, 11] techniques, continue to be essential. Yet the paradigm of structured programming does serve to extend one's powers of design, allowing the construction of programs that are too complicated to be designed efficiently and reliably without methodological support.

 

 

                        Source: Floyd, R. W. (1979). "The paradigms of programming". Communications of the ACM 22 (8): 455.