Английский для пользователей компьютеров. Ч.2. Белобородова М.Л - 20 стр.

 packages, including electronic spreadsheets and database management
 systems, at their fingertips to help them create customized programs to
 solve unique needs. These packages are so much easier to use than typical
 programming languages and procedures that often users who have used a
 computer for just a few hours can develop their own simple applications
 software.
     Regardless of whether a software program is being developed using a high-
 level programming language or an integrated microcomputer software
 package, the same steps should be taken once the program requirements have
 been established: (1) define the problem; (2) map out the program logic—that
 is, work out the necessary algorithms; (3) code the program; (4) test the
 program; and (5) document the program.
     Many tools and techniques are used to document program logic,
 including program flowcharts, pseudocode, structure charts, and HIPO
 packages.
     Program flowcharts use standard symbols to represent the step-by-step
 activities and decision logic needed to solve a processing problem. Logic
 flow normally goes from top to bottom and left to right.
     Pseudocode is a "fake" code—that is, human-language statements that
 use the structure of the programming language statements to describe
 instructions but without being hard to understand. Pseudocode uses four
 keywords to portray logic: IF, THEN, ELSE, and DO. Repetitive
 processing logic is represented by DO WHILE, DO UNTIL, and END DO.
     Structure charts diagram the hierarchy of program modules, each of
 which represents one processing step. HIPO (hierarchy plus input-
 processing-output) packages include a structure chart of the program in
 its visual table of contents along with a program description and a legend.
 The HIPO package also includes an overview diagram, which shows the
 input-processing-output activities of the program modules, and a detail
 diagram, which shows the steps of each activity in a module.
     Programmers use structured programming techniques. Structured
 programming relies heavily on the concept of modularity (top-down design)
 and uses three basic control structures to form the program code: (1) sequence,
 (2) selection (if-then-else), and (3) iteration, or looping (do while).
     The sequence control structure determines that each program instruction is
 executed in sequence unless a particular instruction is intended to alter that
 sequence.
    The selection control structure allows a condition to be tested (IF) to
determine which instruction(s) will be performed next (THEN or ELSE). Using
this structure, the programmer can alter the basic sequence structure.
    The iteration control structure (looping) allows an activity to be repeated as
long as a certain condition remains true. Loops simplify programming because
they enable the programmer to specify instructions only once to have the