I would like to ask you guys a question. You see, I know what a for-loop is for but can someone please maybe explain how one works, just to help me get my head around it, an example is:
for(int i = 0; i < 10; i++) { System.out.println("hello"); } Now obviously that will just print Hello 10 times into the console but that's besides the point, I want to know how the for-loop works.
Sorry if i have confused anyone asking this - Shaun
The for loop in your example is more or less equivalent to this:
int i = 0; while (i < 10) { System.out.println("hello"); i++; } The only difference is that with your for loop, the variable i exists only within the scope of the loop.
Every for loop can be transformed into a while loop using this same pattern.
for (init; test; continuation) { // loop body } becomes:
init; while (test) { // loop body continuation; } Again, the only difference will be with the scope of any variables declared in init.
continue;, i will be incremented, whereas in the while "equivalent" it will not.
continue statement violates the rules of structured programming. (So do return, throws, and break.) It is hard to model it with a while loop. When I used "only", I had in mind OP's specific example; I should have been more careful in my word choice.The for statement provides a compact way to iterate over a range of values. Programmers often refer to it as the "for loop" because of the way in which it repeatedly loops until a particular condition is satisfied. The general form of the for statement can be expressed as follows:
for (initialization; termination; increment) { statement(s) }When using this version of the for statement, keep in mind that:
- The initialization expression initializes the loop; it's executed once, as the loop begins.
- When the termination expression evaluates to false, the loop terminates.
- The increment expression is invoked after each iteration through the loop; it is perfectly acceptable for this expression to increment or decrement a value.
Well, this is how it is set up:
for (a; b; c)
"A" is something that is done at the beginning of the loop. It can actually be left out if necessary, like this:
for (; b; c)
"B" must be a true or false statement (like i<10, it either is or it isn't). Once "b" is no longer true, the loop stops.
"C" is something that is done at the end of the loop.
a, b, and c can be left out of a for loop.
b make it infinite?b, then it is indeed an infinite loop. The only ways out are break, return or throwing an exception.
forconstruct in Java, not about iteration as a concept.