For statement

Statement form

   for loop_var in index_type range low_val..high_val
   loop
	    statement(s);
   end loop;

Examples:

	for i in INTEGER range -1 .. 10 loop
		PUT(i);
		NEW_LINE;
	end loop;


	for i in INTEGER range 1 .. 10 loop
		PUT(i);
		NEW_LINE;
	end loop;


	for i in INTEGER range 2 .. n-1 loop
		PUT(i);
		NEW_LINE;
	end loop;

An example program shows the use of a FOR statement to print a table of numbers and their squares. The number of lines in the table is provided by the user, and so is known at the time when the loop starts executing.

Another example shows how the average number of items over 12 months can be computed, using a FOR loop to process each month in turn.

Rules for for statements

• loop_var is a variable that is not previously declared, it is implicitly declared in the loop, of type index_type, and is called the loop parameter
• within the statement(s) inside the loop, the value of the loop parameter may not be changed
• low_val and high_val may be variables, constants, literals or expressions
• the loop executes at least once provided low_val <= high_val, otherwise it never executes
• the statement(s) may be any Ada statements
• the entire for structure (from for to end loop) is a single Ada statement, terminated by a ;

Style Rules for FOR statements

• statement(s) inside the for are indented by a constant amount
• the end loop is required, and should be at the same indent as the corresponding for

Semantics of FOR statement

Counting down in FOR statements

for loop_var in reverse index_type range low_val .. high_val loop
	statement(s);
end loop;

An example program shows the use of a FOR statement to print a table converting miles per hour to kilometers per hour, with the entries in reverse order.