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+====== Switch statement ======
+**Concepts:**\\
+''switch'' and ''if'' statements, different ways to write and indent a program
+**Text:**\\
+Write a program using the ''if'' or the ''switch'' statement that, given in input a number, recognize the following commands:
+^Command ^Input Number ^
+| Down | 2 |
+| Up | 8 |
+| Left | 4 |
+|Right | 6 |
+**Solution:**\\
+A number of 5 equivalent solutions are reported in the following. Probably, the last one based on the ''switch'' statement, is the more readable.
+**Solution 1:**\\
+This solution is based on the ''if'' statement and on a flag variable ''cmd_executed'' used to specify if a command (i.e., ''2'', ''4'', ''6'', ''8'') has been correctly recognized.
+<file C switch_a.c>
+#include <stdio.h>
+int main(){
+  int cmd;
+  int cmd_executed=0;
+  printf("Insert a command: ");
+  scanf("%d", &cmd);
+  if(cmd==2){
+    printf("Down\n");
+    cmd_executed=1;
+  }
+  if(cmd==8){
+    printf("Up\n");
+    cmd_executed=1;
+  }
+  if(cmd==4){
+    printf("Left\n");
+    cmd_executed=1;
+  }
+  if(cmd==6){
+    printf("Right\n");
+    cmd_executed=1;
+  }
+  if(!cmd_executed){
+    printf("ERROR: incorrect command!\n");
+  }
+  return 0;
+}
+</file>
+**Solution 2:**\\
+This solution is based only on the ''if'' statement, without the used of the flag variable
+<file C switch_b.c>
+#include <stdio.h>
+int main(){
+  int cmd;
+  printf("Insert a command: ");
+  scanf("%d", &cmd);
+  if(cmd==2){
+    printf("Up\n");
+  }else{
+    if(cmd==8){
+      printf("Down\n");
+    }else{
+      if(cmd==4){
+	printf("Left\n");
+      }else{
+	if(cmd==6){
+	  printf("Right\n");
+	}else{
+	    printf("ERROR: incorrect command!\n");
+	}
+      }
+    }
+  }
+  return 0;
+}
+</file>
+**Solution 3:**\\
+Same as //Solution 2//, but without braces in the ''if'' statement.
+<file C switch_c.c>
+#include <stdio.h>
+int main(){
+  int cmd;
+  printf("Insert a command: ");
+  scanf("%d", &cmd);
+  if(cmd==2)
+    printf("Down\n");
+  else
+    if(cmd==8)
+      printf("Up\n");
+    else
+      if(cmd==4)
+	printf("Left\n");
+      else
+	if(cmd==6)
+	  printf("Right\n");
+	else
+	    printf("ERROR: incorrect command!\n");
+  return 0;
+}
+</file>
+**Solution 4:**\\
+This solution is exactly equivalent to the one reported in //Solution 3//, only indentation changes
+<file C switch_d.c>
+#include <stdio.h>
+int main(){
+  int cmd;
+  printf("Insert command: ");
+  scanf("%d", &cmd);
+  if(cmd==2)
+    printf("Down\n");
+  else if(cmd==8)
+    printf("Up\n");
+  else if(cmd==4)
+    printf("Left\n");
+  else if(cmd==6)
+    printf("Right\n");
+  else
+    printf("ERROR: incorrect command!\n");
+  return 0;
+}
+</file>
+**Solution 5:**\\
+Finally, this solution is based on the use of the ''switch'' statement
+<file C switch_e.c>
+#include <stdio.h>
+int main(){
+  int cmd;
+  printf("Insert command: ");
+  scanf("%d", &cmd);
+  switch(cmd){
+  case 2:
+    printf("Down\n");
+    break;
+  case 8:
+    printf("Up\n");
+    break;
+  case 4:
+    printf("Left\n");
+    break;
+  case 6:
+    printf("Right\n");
+    break;
+  default:
+    printf("ERROR: incorrect command!\n");
+  }
+  return 0;
+}
+</file>

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