do-until statement is similar to the
except that it repeatedly executes a statement until a condition becomes
true, and the test of the condition is at the end of the loop, so the
body of the loop is always executed at least once. As with the
condition in an
if statement, the condition in a
statement is considered true if its value is non-zero, and false if its
value is zero. If the value of the conditional expression in a
do-until statement is a vector or a matrix, it is considered
true only if it is non-empty and all of the elements are non-zero.
do-until statement looks like this:
do body until (condition)
Here body is a statement or list of statements that we call the body of the loop, and condition is an expression that controls how long the loop keeps running.
This example creates a variable
fib that contains the first ten
elements of the Fibonacci sequence.
fib = ones (1, 10); i = 2; do i++; fib (i) = fib (i-1) + fib (i-2); until (i == 10)
A newline is not required between the
do keyword and the
body; but using one makes the program clearer unless the body is very