Random Led Blinker

1int yellow=2;
2int red=5;
3int green=8;
4int blue=12;
5
6void  setup() {
7  // put your setup code here, to run once:
8  Serial.begin(9600);
9  pinMode(yellow,OUTPUT);
10  pinMode(red,OUTPUT);
11  pinMode(green,OUTPUT);
12  pinMode(blue,OUTPUT);
13}
14
15void loop() {
16  // put your main code here,  to run repeatedly:
17    int a = random(1,5);
18
19    switch(a){
20      case  1:
21        digitalWrite(yellow,HIGH);
22        delay(1000);
23        digitalWrite(yellow,LOW);
24        break;
25
26      case 2:
27        digitalWrite(red,HIGH);
28        delay(1000);
29        digitalWrite(red,LOW);
30        break;
31
32      case 3:
33        digitalWrite(green,HIGH);
34        delay(1000);
35        digitalWrite(green,LOW);
36        break;
37
38      case 4:
39        digitalWrite(blue,HIGH);
40        delay(1000);
41        digitalWrite(blue,LOW);
42        break;
43    }
44}