do

14.11 The do Statement

The do statement executes a Statement and an Expression repeatedly until the value of the Expression is false.

DoStatement:

do Statement while ( Expression ) ;

The Expression must have type boolean, or a compile-time error occurs.

A do statement is executed by first executing the Statement. Then there is a choice:

Executing a do statement always executes the contained Statement at least once.

14.11.1 Abrupt Completion

Abrupt completion of the contained Statement is handled in the following manner:

14.11.2 Example of do statement

The following code is one possible implementation of the toHexString method of class Integer:


public static String toHexString(int i) {
  StringBuffer buf = new StringBuffer(8);
  do {
    buf.append(Character.forDigit(i & 0xF, 16));
    i >>>= 4;
  } while (i != 0);
  return buf.reverse().toString();
}

Because at least one digit must be generated, the do statement is an appropriate control structure.