for loops in Python always go forward. If you want to be able to move backwards, you must use a different mechanism, such as while: i = 0 while i < 5: print(i) if condition: i=i-1 i += 1 Or even better: i = 0 while i < 5: print(i) if condition: do_something() # don’t … Read more
You could do this, though probably not as slick as you’d like: declare type nt_type is table of number; nt nt_type := nt_type (1, 3, 5); begin for i in 1..nt.count loop dbms_output.put_line(nt(i)); end loop; end; If you create a type in the database: create type number_table is table of number; then you can do … Read more
You need to escape the | character to prevent its being interpreted at the time of parsing the loop command. Use ^ to escape it: FOR /f “delims=” %%A in (‘dir /b “my_dir\*.csv” ^| find /V “summary”‘) do ( rem do what you want with %%A here ) Once escaped, the | becomes part of … Read more
It’s a bit of an oversimplification to say that the enhanced for loop is more efficient. It can be, but in many cases it’s almost exactly the same as an old-school loop. The first thing to note is that for collections the enhanced for loop uses an Iterator, so if you manually iterate over a … Read more
Yes, semantically it will be evaluated on every loop. In some cases, compilers may be able to remove the condition from the loop automatically – but not always. In particular: void foo(const struct rect *r) { for (int i = 0; i < r->width * r->height; i++) { quux(); } } The compiler will not … Read more
One way to translate an imperative for loop to Clojure is to use the for macro. (for [i (range 10)] (inc i)) The above function will return all the numbers from 0 to 9 incremented by 1. However, it appears you simply want to iterate over a sequential collection and use each item. If that’s … Read more
Its most likely because in this for loop style (for..in), it is treating i as a key, and since keys in objects are usually strings (yes, an array is a type of object in javascript), it is treating it as a String. parseInt(i) works in this situation, but for good programming practice, you would want … Read more
The comma operator evaluates all its operands and yields the value of the last one. So basically whichever condition you write first, it will be disregarded, and the second one will be significant only. for (i = 0; j >= 0, i <= 5; i++) is thus equivalent with for (i = 0; i <= … Read more
The for…in statement is meant to be used to iterate over object properties, by looking your code seems that actors is an Array (you are setting the initial element with index 0). This statement will also crawl up the prototype chain, if you have extended the Array.prototype those properties will be iterated, and also the … Read more
Your code works. If you don’t have any output, you may have “forgotten” to add some values to the list: // add values list.add(“one”); list.add(“two”); // your code for (String object: list) { System.out.println(object); }