The do loop

In a while loop, the condition of end of loop is checked at the beginning of each iteration. A do loop is similar to a while loop, with the only difference that the condition of end of loop is checked at the end of each iteration.

do statement

Syntax:

do
  statement
while (condition);

• condition is an expression of type boolean
• statement is a single statement (also called the body of the loop)

Semantics: is equivalent to

statement;
while (condition)
  statement

Hence:

• First, the statement is executed.
• Then, the condition is evaluated, and if it is true, the statement is executed again, continuing in this way until the condition becomes false.
• At this point the statement immediately following the do loop is executed.

Example: Print out 100 stars.

int i = 0;
do {
  System.out.print("*");
  i++;
} while (i < 100);