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IF & SWITCH (conditional control) in computer science
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- 2. Conditional Control Flow • Conditionalcontrol flow is also referred to as conditional logicor selection logic. • It is one of the order in which the program instructions are executed. • Its execution order differs from the sequential logic. • It executes the instructions on the basis of one or more conditions. • If the conditions are satisfied it will execute the instructions else the instructions will not be executed (skipped).
- 3. Conditional Control Flow In conditionallogic: • Statements are executed on the basisof conditions. • If conditions are satisfied the statements are executed. • If conditions are not satisfied the statements are skipped.
- 4. Conditional Control Structuresin C++ • Conditional control structures are used to execute set of statements on the basis of one or more conditions. • The statements that are needed to be executed conditionally are placed with in the conditional structures and one or more conditions are specified. • The conditional control structures implement the conditional/selection logic in C++.
- 5. if Statement in C++ •if statement implements one-way selection logic. • It executes the statement(s) on the basis of one condition. • If the condition is true, it executes if block. • If the condition is false, it does not execute if block.
- 6. if Statement – Syntax if( condition ) { statement set ; } if ( condition ) statement ;
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- 8. if Statement – Syntax •There are two syntaxes of if statement. • In first syntax we have multiple statements inside the if statement. • In this case it is compulsory to enclose all the statements in the braces { } . • In second syntax we have just one statement inside the if statement. • In this case it is optional to enclose the statement in thebraces { } . • All the statements enclosed in {} is called as the block.
- 9. if Statement –Flow Chart
- 10. if Statement - Example ProblemStatement 1: If the number is positive thendisplay it.
- 11. if Statement - Example ProblemStatement 2: If the number is multiple of 5 then add 1 to it and display the resultant number.
- 12. If-else Statement in C++ •If-else statementimplements two-way selection logic. • It executes the statement(s) on the basis of one condition. • If the condition is true, it executes if block. • If the condition is false, itexecutes else block.
- 13. If-else Statement – Syntax if( condition ) { statement set 1 ; } else { statement set 2 ; if ( condition ) statement set 1 ; else statement set 2 ;
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- 16. If-else Statement – Syntax •There are two syntaxes of if-else statement. • In first syntax we have multiple statements inside the if-else statement. • In this case it is compulsory to enclose all the statements in the braces { } . • In second syntax we have just one statement inside the if-else statement. • In this case it is optional to enclose the statement in thebraces { } .
- 17. If-else Statement –Flow Chart
- 18. if-else Statement - Example ProblemStatement 1: If the number is even, display “Number is even” else display “Number is odd”.
- 19. switch Statement in C++ •switch implements choice-way selection logic. • It executes the statement(s) on the basis of expression and available choices. • It first evaluates the expression and matches the value of expression to available choices (cases). • If the value matches with first case, then case 1 body is executed. • If the value matches with second case, then case 2 body is executed. • And the process continues up to nth case. • If the value does not matches with any of the case, then default case body is executed.
- 20. switch Statement – Syntax switch( expression ) { case 1 : statement set 1 ; break ; case 2 : statement set 2 ; break ; case 3 : statement set 3 ; break ; default :
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- 22. switch Statement – Syntax •In switch statement, first the expression is evaluated to a single value. • In expression we can only use the value of data types: char, short,int and long. No any other data types is accepted. • We cannot use relational operation in switch statement. • switch statement always contain one expression and multiple cases. Where each case is ended by break statement. • Last case is the default case (it is optional), it is executed when the evaluated value does not match with any of thecase.
- 23. switch Statement –Flow Chart
- 24. switch Statement - Example ProblemStatement: Give remarks to the student according to the marks he/she gets out of 5 in the sessionaltest.