The for Loop
Ok, so the for loop. This is a useful looping structure for traversing through arrays and such. Let's take a look at the syntax shall we?
for (int x = 0; x < 100; x++)
{
// statements to execute 100 times
}
The for line, let's take a closer look at it...It starts with the for keyword of course, to signify that a loop follows. In the parentheses we have the loop control variable, x, which starts at zero (the first part, before the semicolon). The second part is what to stop at, in this case, 99, since x cannot be greater than or equal to 100. The third part is the value to increment by every time the end of the loop iteration is reached, in this case our shortcut is used for add 1 every time.
The while Loop
The while loop. A loop to continue going around...and around, and around until a certain condition is reached. Let's take a look at the syntax for this one.
int x = 5;
while (x < 10)
{
System.out.println(x);
x++;
}
Well, not much to explain here, just put in the parentheses after while whatever you want the condition to stop, to be.
The do-while Loop
The do-while. This is much the same as the while loop, with only 1 difference. It MUST execute at least once, as it doesn't know what the condition to stop is, until after it executes the code once.
int number = 10;
do
{
System.out.println(number);
number += 10;
}
while (number <= 100);
Well, there's one major difference between the while line in the regular while loop, and this one. Notice the semicolon, as this must be there for a do-while loop, as it signifies the end of the statement of the do-while loop. In other words, it just signifies the end.
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Modification Section:
The for each Loop
NOTE: To use this loop you must have JDK 1.5 or later, as that was when this loop was created.
Well, this is useful for traversing arrays in a different manner. It just goes for the entire length of the array, or ArrayList.
// our 'int' array, NUMBERS, is pre-defined
for (int number : NUMBERS)
System.out.println(number);
The basic syntax for this is for (variable_to_use_inside_the_loop : array_to_look_in). It's the same as doing a for (int x = 0; x < NUMBERS.length; x++).
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This has been my basic introduction to java looping. It's not a very in-depth tutorial, but it's not supposed to be. Then again, looping is a fairly routine and easy thing to accomplish.
Hope this helped!
This post has been edited by Locke37: 01 August 2008 - 10:40 PM
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