Introduction to OOPs
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1.1 STRUCTURED INTRODUCTION
Structured programming (known as modular programming) is a subset of procedural programming that enforces a logical structure in the programming being written, to make it more efficient and easier to understand and modify. Structured programming frequently employs a top-down design model, in which developers map out the overall program structure into separate subsections. A defined function or a set of similar functions coded in separate modules can be reused in other programs. After a module has been tested individually, it is then integrated with other modules into the overall program structure. Program flow follows a simple hierarchical model that employs looping constructs such as 'for,' 'repeat' and 'while.' Use of the 'Go To' statement is discouraged in structured programming.
Structured programming was first suggested by the mathematicians Corrado Bohm and Guiseppe Jacopini. They demonstrated that any computer program can be written with just three structures: decision, sequences and loops.
In structured programming coders break larger pieces of code into shorter subroutines (functions, procedures, methods, blocks or otherwise) that are small enough to be understood easily. In general, programs should use local variables and take arguments by either value or reference. These techniques help to make isolated small pieces of code easier to understand the whole program at once. PASCAL, Ada and C are some of the examples of structured programming languages.
1.1.1 Sequence Structure
A sequence structure consists of a single entry and single exit statement, i.e., it makes a sequential flow (Figure 1.1).
1.1.2 Loop or Iteration Structure
The loop consists of a sequence of statements, which are executed based on the logical condition. (Figure 1.2)
1.1.3 Decision