We have already seen if, which allows us to make a decision whether to execute a block of code based upon the result of its expression. Sometimes a decision in C++ can be better made in other ways.

When we have to make a decision based on a clear list of possible outcomes, which doesn't involve complex combinations or wide ranges of values, then switch is usually the way to go. We start a switch decision as we can see in the following code:

switch(expression) 
{ 
 
   // More code here 
} 

In the previous example, expression could be an actual expression or just a variable. Then, within the curly braces, we can make decisions based on the result of the expression or the value of the variable. We do this with the case and break keywords:

case x: 
    //code to for x 
    break; 
  
case y: 
    //code for y 
    break; 

You can see in the previous abstract example that, each case states a possible result and each break denotes the end of that case and the point at which execution leaves the switch block.

We can also, optionally, use the default keyword without a value, to run some code in case none of the case statements evaluate to true. Here is an example:

default: // Look no value 
    // Do something here if no other case statements are true 
    break; 

As a final and less abstract example for switch, consider a retro text adventure where the player enters a letter such as 'n', 'e', 's', or 'w' to move North, East, South, or West. A switch block could be used to handle each possible input from the player, as we can see in this example:

// get input from user in a char called command 
 
switch(command){ 
 
   case 'n': 
      // Handle move here 
      break; 
 
   case 'e': 
      // Handle move here 
      break; 
 
   case 's': 
      // Handle move here 
      break; 
 
   case 'w': 
      // Handle move here 
      break;    
    
   // more possible cases 
 
   default: 
      // Ask the player to try again 
      break; 
 
} 

The best way of understanding everything we have learned about switch will be when we put it into action along with all the other new concepts we are learning.