Welcome reader,
This will be the final part in the programming basics mini series in how to manage the program flow of your software application. We’re going to see how to manage the flow of your program when we’re using a switch. It is a structure that is mostly use when we have predefined conditions.When this happen, knowing exactly those condition, we’ll have the correct operation to perform if it is met. For example, when someone is doing an exam, we could have three states
- He didn’t know what to do, so he had a 0
- The knowledge on the topic was not mastered he managed to get 11 out of 25
- The student mastered the topic and had 25 out of 25
If conditions like these we found in our application, it would be better to use a switch instead of the if-else if – else structure because we’ll have less to write. We’ll see below the structure of a switch statement :
/*
Everything in this code will not work
it is used to demonstrate how a switch statement is written
*/
switch (aVariable)
{
case /*ValueOfAVariable*/:
/*Operation*/;
break; //tells the computer to stop the operation in this case
default: //Represent what to do if no condition is met
/*Operation*/;
}
In a swich statement, a case represents the value of the variable we’re evaluating in the switch. If a case is met, then all the operations for this case will be perform until the machine find the line with a break statement. Moreover, the cases can be link altogether. Like it was said before, until the computer find the statement “break;”, the switch will continue to operate. Below, we’ll see an example of such a switch:
switch(value)
{
case 1:
case 2:
case 3:
case 4:
//do some stuff
break;
case 5:
case 6:
//do other stuff
break;
default:
//do some default stuff
break;
}
Also, we have the ternary operator, which embeds the way the if-else structure work. We’ll be able to find the structure of the ternary operator below for when you want to assign a value to a variable:
- dataType variable = ( aCondition) ? (firstValue) : (secondValue) ;
The ternary operator evaluates the given condition. If it is true, firstValue will be assign to variable. If the condition was to be false in our program, then secondValue would be assigned to variable. We’ll try out a code sample to see how it could be useful:
int minValue=15;
int midValue=30;
int maxValue=45;
int aMaxValue=(midValue>maxValue) ? midValue : maxValue;
All of this covers how to manage the program flow in your software application. If for the moment this does not look useful, in the next posts, it will get more clear as we get deeper into programming as our knowledge of the basics gets better.
Kevin
