1 difference:
If the conditional never been satisfied, then the for loop and while loop will be executed zero times, but do-while loop will execute at least once. Recommended for use when the known number of cycles, when an unknown number of cycles is recommended while.
2 difference
Variables for loop in parentheses among definition, only the inner loop can be used. while loops and do-while loop initialization statement already outside, so after the cycle can continue to use it.
Code Example
public class Demo13LoopDifference { public static void main (String [] args) { for ( int I =. 1; I <0; I ++ ) { System.out.println ( "the Hello" ); } // System.out.println (I ); // this line is wrong wording! Because the variable i is defined within a for loop parentheses, only for circulation to their own use. System.out.println ( "================" ); int I =. 1 ; do { System.out.println ( "World" ); I ++ ; } the while (i <0); // now is beyond the scope of the do-while loop, we can still use the variable i System.out.println (i); // 2 } }
Results of the