Arduino voice control smart home

1#define fan 2    
2#define bulb 3
3#define light 4
4
5
6void   setup() {
7  // put your setup code here, to run once:
8  Serial.begin(9600);
9   pinMode(fan, OUTPUT);
10  pinMode(bulb, OUTPUT);
11  pinMode(light, OUTPUT);
12}
13
14void   loop() {
15  // put your main code here, to run repeatedly:
16  if(Serial.available()   == 1)
17  
18  {
19    String val = Serial.readString();
20    Serial.println(val);
21     if(val == "fan on")
22    {
23      digitalWrite(fan, HIGH);
24    }
25     if(val == "fan off")
26    {
27      digitalWrite(fan, LOW);
28    }
29     if(val == "bulb on")
30    {
31      digitalWrite(bulb, HIGH);
32    }
33     if(val == "bulb off")
34    {
35      digitalWrite(bulb, LOW);
36    }
37     if(val == "light off")
38    {
39      digitalWrite(light, LOW);
40    }
41     if(val == "light on")
42    {
43      digitalWrite(light, HIGH);
44    }
45     if(val == "all on")
46    {
47      digitalWrite(fan, HIGH);
48      digitalWrite(bulb,   HIGH);
49      digitalWrite(light,HIGH);
50    }
51    if(val == "all off")
52     {
53      digitalWrite(bulb, LOW);
54      digitalWrite(fan, LOW);
55      digitalWrite(light,   LOW);
56    }
57  }
58}