java - When are curly braces not required for multi-line loop bodies? -

why code behave correctly? i've been told multi-line loop bodies should have curly braces

public class sample {      public static void main(string[] args)     {         int[] nums = {1,2,3,4,5,6,7,8,9,10};          // print out whether each number         // odd or         (int num = 0; num < 10; num++)             if (num % 2 == 0)                 system.out.println(num + " even");             else                 system.out.println(num + " odd");     } } 

the trick here difference between statement , line. loop bodies execute next statement, unless there curly braces, in case loop execute whole block inside curly braces. (as mentioned in other answers, always practice use curly braces every loop , if statement. makes code easier understand, , easier correctly modify.)

to specific example:

an if-else statement in java considered single statement.

in addition, following valid single-line statement:

if(someboolean)     someaction(1); else if (someotherboolean)     someotheraction(2); else     yetanotheraction(); 

you add many else-if's wanted, , compiler still view single statement. however, if don't use else, views separate line. example:

for(int a=0; a<list.size; a++)     if(list.get(a) == 1)         someaction();     if(list.get(a) == 2)         someotheraction(); 

this code won't compile, because second if statement outside scope of for loop, hence int a doesn't exist there.