I was making a new code where my objective was to make whatever key you press make my little "truck" go forward. I was trying to do this by adding spaces to my string, which was my truck.
String truck = "<o><o>-<o>~|#|¬";
truck = new StringBuffer(truck).insert(0, " ").toString();
System.out.println(truck);
I would like to know how to do a "loop" on this, where it add spaces with the quantity of keys that you pressed. Thanks for reading, have a nice day.
You could do this in a number of ways, for example...
You could attack the problem head on, for example...
StringBuilder sb = new StringBuilder(truck);
for (int index = 0; index < length; index++) {
sb.append(0, " ");
}
truck = sb.toString();
You could write a method which produced an "empty" String
public String createPath(int length) {
StringBuilder sb = new StringBuilder(length);
for (int index = 0; index < length; index++) {
sb.append(" ");
}
return sb.toString();
}
Then simply append the result, for example...
truck = createPath(n) + truck;
Or you could be really tricky and simply use String.format...
public String createPath(int length) {
return String.format("%" + length + "s", "");
}
Without going into the nuances of capturing keypresses or any of that, you presumably just want a while loop to continue to "drive" your truck until the user quits (or whatever). A very simple one might look like this:
String truck = "<o><o>-<o>~|#|¬";
int count = 0;
while(true) { // This is your loop
int n = 1; // or capture some user input, etc...
// Then "move" the truck
StringBuilder sb = new StringBuilder();
for(int i=0; i<n+count; i++) {
sb.append(" ");
}
sb.append(truck);
System.out.println(sb.toString());
count = count + n;
}
This method generates the String you want to print. As you did not mention the way you want to listen to, it is omitted.
public String truck(int n) {
String truck = "<o><o>-<o>~|#|¬";
StringBuilder sb = new StringBuilder();
for (int i = n; i-->0;)
sb.append(' ');
sb.append(truck);
return sb.toString();
}
The loop in more ordinary form is:
for (int i = 0; i < n; i++)
sb.append(' ');
(I prefer the former when applicable, because the computation for n is done only once, and I have to specify the loop variable only once in the loop declaration.)
Try to do it this way:
public String truck(int countOfHits){
StringBuilder sb = new StringBuilder("<o><o>-<o>~|#|¬");
sb.reverse();
for(int i = 0; i <= countOfHits; i++){
sb.append(" ");
}
return sb.reverse().toString();
}
If you think about it, you realize that this will turn an O(n²) solution into O(n).
