Bài giảng Tin học đại cương - Chương 2: Control structures

1 Chapter 2 - Control Structures Outline ③ Control Structures ③ if Selection Structure ③ if/else Selection Structure ③ while Repetition Structure ③ Formulating Algorithms: Case Study 1 (Counter-Controlled Repetition) ③ Formulating Algorithms with Top-Down, Stepwise Refinement: Case Study 2 (Sentinel-Controlled Repetition) ③ Formulating Algorithms with Top-Down, Stepwise Refinement: Case Study 3 (Nested Control Structures) ③ Assignment Operators ③ Increment and Decrement Operators ③ Essentials of Counter-Controlled Repetition ③ for Repetition Structure ③ switch Multiple-Selection Structure ③ do/while Repetition Structure ③ break and continue Statements ③ Logical Operators ③ Confusing Equality (==) and Assignment (=) Operators ③ Structured-Programming Summary  2003 Prentice Hall, Inc. All rights reserved. 2 Control Structures • Sequential execution – Statements executed in order • Transfer of control – Next statement executed not next one in sequence • 3 control structures (Bohm and Jacopini) – Sequence structure • Programs executed sequentially by default – Selection structures •if, if/else, switch – Repetition structures •while, do/while, for  2003 Prentice Hall, Inc. All rights reserved. 3 Control Structures • C++ keywords – Cannot be used as identifiers or variable names C++ Keywords Keywords common to the C and C++ programming languages auto continue enum if short switch volatile C++ only keywords asm delete inline private static_cast try wchar_t break default extern int signed typedef while bool dynamic_cast mutable protected template typeid case do float long sizeof union catch explicit namespace public this typename char double for register static unsigned class false new reinterpret_cast throw using const else goto return struct void const_cast friend operator true virtual  2003 Prentice Hall, Inc. All rights reserved. 4 if Selection Structure • in C++ If student’s grade is greater than or equal to 60 Print “Passed” if ( grade cout << >= 60 ) "Passed"; A decision can be made on any expression. grade >= 60 true print “Passed” zero - false nonzero - true Example: false 3 - 4is true  2003 Prentice Hall, Inc. All rights reserved. 5 if/elseSelection Structure •if – Performs action if condition true •if/else – Different actions if conditions true or false • Pseudocode if student’s grade is greater than or equal to 60 print “Passed” else print “Failed” • C++ code if ( grade cout << else cout << >= 60 ) "Passed"; "Failed";  2003 Prentice Hall, Inc. All rights reserved. ... - tailieumienphi.vn