This is a bit like a roundabout.
It's a control structure.
It lets you choose from many different routes.... depending of the value of a variable.
It's like a series of "if" statements.
Good for menus... keeps everything tidy.
It starts with the word switch().
Then in the parenthesis, you type the name of the variable that determines the case
The break keyword exits the switch statement, and is typically used at the end of each case.
Example 1
Many thanks to Programming Electronics for the example.
The circuit: * 5 LEDs attached to digital pins 2 through 6 through 220-ohm resistors created 1 Jul 2009 by Tom Igoe This example code is in the public domain. http://www.arduino.cc/en/Tutorial/SwitchCase2
//************************************************************
/*
Switch statement with serial input
Demonstrates the use of a switch statement. The switch
statement allows you to choose from among a set of discrete values
of a variable. It's like a series of if statements.
To see this sketch in action, open the Serial monitor and send any character.
The characters a, b, c, d, and e, will turn on LEDs. Any other character will turn
the LEDs off.
The circuit:
* 5 LEDs attached to digital pins 2 through 6 through 220-ohm resistors
created 1 Jul 2009
by Tom Igoe
This example code is in the public domain.
http://www.arduino.cc/en/Tutorial/SwitchCase2
*/
void setup() {
// initialize serial communication:
Serial.begin(9600);
// initialize the LED pins:
for (int thisPin = 2; thisPin < 7; thisPin++) {
pinMode(thisPin, OUTPUT);
}
}
void loop() {
// read the sensor:
if (Serial.available() > 0) {
int inByte = Serial.read();
// do something different depending on the character received.
// The switch statement expects single number values for each case;
// in this exmaple, though, you're using single quotes to tell
// the controller to get the ASCII value for the character. For
// example 'a' = 97, 'b' = 98, and so forth:
switch (inByte) {
case 'a':
digitalWrite(2, HIGH);
break;
case 'b':
digitalWrite(3, HIGH);
break;
case 'c':
digitalWrite(4, HIGH);
break;
case 'd':
digitalWrite(5, HIGH);
break;
case 'e':
digitalWrite(6, HIGH);
break;
default:
// turn all the LEDs off:
for (int thisPin = 2; thisPin < 7; thisPin++) {
digitalWrite(thisPin, LOW);
}
}
}
}//***********************************************************************
Links
+ https://www.arduino.cc/reference/tr/language/structure/control-structure/switchcase/
+ https://www.programmingelectronics.com/tutorial-14-5-switch-case-statement-old-version/
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