Switch
1) Switch statement is used to take multiple selections. 

2) Curly brasses are mandatory if we are not taking we are getting compilation error. 

3) Inside the switch It is possible to declare any number of cases but is possible to declare only one default. 

4) Switch is taking the argument the allowed arguments are
a. Byte
b. Short
c. Int
d. Char
e. String(allowed in 1.7 version) 

5) Float and double and long is not allowed for a switch argument because these are having more number of possibilities (float and double is having infinity number of possibilities) hence inside the switch statement it is not possible to provide float and double and long as a argument.
6) If the case is matched particular case will be executed if there is no case is matched default case is executed.

Syntax:

switch (key) {
case value:

break;

default:
break;
}
Java Images
Switch program
class Test 
{ 
public static void main(String[] args) 
{ 
int a=10; 
switch (a) 
{ 
case 10:System.out.println("10"); 
break; 
case 20:System.out.println("20"); 
break; 
case 30:System.out.println("30"); 
break; 
case 40:System.out.println("40"); 
break; 
default:System.out.println("default"); 
break; 
} 
} 
}
Output :
output:10
switch program using provide constant expressions
class Test 
{ 
public static void main(String[] args) 
{ 
int a=300; 
switch (a) 
{ 
case 10+20+70:System.out.println("10"); 
break; 
case 100+200:System.out.println("20"); 
break; 
default :System.out.println("default"); 
break; 
} 
} 
};
Output :
output:20
switch program without break
class Test 
{ 
public static void main(String[] args) 
{ 
int a=10; 
switch (a) 
{ 
case 10:System.out.println("10"); 
case 20:System.out.println("20"); 
case 30:System.out.println("30"); 
case 40:System.out.println("40"); 
break; 
default: System.out.println("default"); 
break; 
} 
} 
}
Output :
output:10,,20,,30,,40
string argument using switch statement
class free
{ 
public static void main(String[] args) 
{ 
String str = "bbb"
switch (str) 
{ 
case "aaa" : System.out.println("Hai"); 
break;
case "bbb" : System.out.println("bye"); 
break; 
case "ccc" : System.out.println("how"); 
break; 
default : System.out.println("what"); 
break; 
} 
} 
}
Output :
Output:-bye
char argument using switch statement
class Test 
{ 
public static void main(String[] args) 
{ 
char ch='a'; 
switch (ch) 
{ 
case 'a' : System.out.println("a"); 
break; 
case 'b' : System.out.println("b"); 
break; 
case 'c' : System.out.println("c"); 
break; 
default : System.out.println("d"); 
break; 
} 
} 
}
Output :
output:a