how to do case in c++ code example

Example 1: switch c++

switch(expression) {
   case 1:
      //equivalent to if(expression == 1){//do someting...}
      //do something...
      break; 
    //if case 1 is true the rest of the statments arn't 
    //evaluated because of the break
   case 45:
      //equivalent to else if(expression == 45){//do someting...}
      //do something...
      break;
    
   // you can have any number of case statements and default has to be last
   default :
      // equivalent to else{//do someting...}
      //do something...
}

switch(expression) {
   case 1:
      //equivalent to if(expression == 1){//do someting...}
      //do something...
   case 45:
      //equivalent to if(expression == 45){//do someting...}
      //do something...
   default :
      //always runs if there are no breaks in any of the cases
      //do something...
}

//modification of answer by Homeless Hoopoe

Example 2: switch statement c++

switch(expression) {
   case constant-expression  :
      statement(s);
      break; //optional
   case constant-expression  :
      statement(s);
      break; //optional
  
   // you can have any number of case statements.
   default : //Optional
      statement(s);
}