Monday, 8 April 2019

4. DECISION-MAKING STATEMENTS (PART-2)

     DECISION-MAKING STATEMENTS 


When the above code is compiled and executed, it produces the following result: 


Value of a is not matching 

Exact value of a is : 100 

Switch Statement 
 A switch statement allows a variable to be tested for equality against a list of values. Each value is called a case, and the variable being switched on is checked for each case. 

Syntax 

 The syntax for a switch statement in C++ is as follows: 



The following rules apply to a switch statement: 
 • The expression used in a switch statement must have an integral or enumerated type, or be of a class type in which the class has a single conversion function to an integral or enumerated type. 
 • You can have any number of case statements within a switch. Each case is followed by the value to be compared to and a colon. 
 • The constant-expression for a case must be the same data type as the variable in the switch, and it must be a constant or a literal. 
 • When the variable being switched on is equal to a case, the statements following that case will execute until a break statement is reached. 
 • When a break statement is reached, the switch terminates, and the flow of control jumps to the next line following the switch statement. 
 • Not every case needs to contain a break. If no break appears, the flow of control will fall through to subsequent cases until a break is reached. 
 • A switch statement can have an optional default case, which must appear at the end of the switch. The default case can be used for performing a task when none of the cases is true. No break is needed in the default case. 

Flow Diagram :









This would produce the following result: 



You passed 

Your grade is D 

Nested if Statement 
 It is always legal to nest if-else statements, which means you can use one if or else if statement inside another if or else if statement(s). 




When the above code is compiled and executed, it produces the following result: 


Value of a is 100 and b is 200 

Exact value of a is : 100 

Exact value of b is : 200 





Nested switch Statements 

 
It is possible to have a switch as part of the statement sequence of an outer switch. Even if the case constants of the inner and outer switch contain common values, no conflicts will arise. 

C++ specifies that at least 256 levels of nesting be allowed for switch statements. 
 
Syntax 
 The syntax for a nested switch statement is as follows: 











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