The while-statement tests the expression in parenthesis, and executes the statements enclosed within braces until the expression is false. The expression must evaluate to a scalar-expression. If the expression evaluates to a vector or matrix a run-time error will result.
while ( expression )
{
statements
}
> while ( 0 ) { "TRUE" } > i = 0; > while ( i < 2 ) { i = i + 1 } i = 1 i = 2