Unreachable statement

[Sireesha Mullapudi]

Hi,
Why 1& 4 are unreachable in the below code

public class Question38 {
public static void main(String[] args){
while(false);//line 1
if(false);//line 2
do{}while(false);//line 3
        for(;false;);//line 4
}
}

Thanks,SCJP1.4


[HENRY: Added code tags. Fixed formatting.]
[ November 01, 2006: Message edited by: Henry Wong ]

[prashanth kumar]

Since you havent used "CODE" tag,your code is not properly formatted..

Now i can only see line 1 properly which is

while(false);

Here ";" is an empty statement and since false is hardcoded in while loop,";" never gets executed under any circumstances..And hence the compiler error

All The Best

[Sireesha Mullapudi]

Hi,
This is tthe code

public class Question38 {
public static void main(String[] args){
while(false);//line 1
if(false);//line 2
do{}while(false);//line 3
for(;false :wink: ;//line 4
}
}    

[Henry Wong]

line 1: Even though the while loop only has an "empty" statement, this statement is still considered unreachable because the while loop can never be true.

line 4: Even though the for loop only has an "empty" statement, this statement is still considered unreachable because the for loop can never be true.

line 3: The check for a do loop executes at the end of the loop. This means that a do loop will execute at least once, regardless of whether it is true or false. The body is always reachable.

line 2: Technically this if statement's body is unreachable -- but this is allowed in the specifications. The reason that this is allowed is to provided for conditional code -- like debugging code.

Henry